The Atlas That Redrew the World
How Mapmakers Shaped Borders, Beliefs and Empires
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Chapter three examines how cartography evolved from ancient techniques to satellite technology, including the famous Mercator projection that distorted Greenland's size. The work explores how colonial powers drew arbitrary boundaries across Africa, creating conflicts that persist today. It also covers the Peters projection controversy and how different map views influence public perception of global power structures.
The final chapters focus on recent American political developments, including redistricting cycles and congressional elections. These sections show how modern mapmaking directly affects voting power and representation. Anyone interested in understanding how borders are drawn and why they matter will find this book essential reading.
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Overview
Maps are among humanity’s most vital inventions, helping people understand and move through their world. It's unknown exactly when the first maps appeared, but evidence suggests they arose independently across many cultures—early examples may be cave paintings or carvings on stone and tusks. Civilizations like Babylon, Greece, Rome, China, and India all made maps. Early ones didn’t account for Earth’s curve, since that wasn't known and wasn’t necessary for small areas. But starting in Classical Greece, cartographers began using globe-based projections to manage distortions in larger maps, especially world maps. Today, modern tools like satellites and online platforms such as Google Earth have made detailed global mapping possible in ways previous generations couldn’t imagine.
Ancient Near East
In ancient Babylonia, mapmakers used precise surveying methods, as shown on a clay tablet from around 2500–2400 BC found near Kirkuk. It depicts a valley with labeled features, including land owned by someone named Azala. The Babylonian World Map, dating to about 600 BC, represents the world symbolically rather than literally, omitting known peoples like Persians and Egyptians, and shows a circular landmass surrounded by water, reflecting Babylonian beliefs. Meanwhile, Phoenician sailors made major advances in seafaring; Herodotus records that explorers working for Egyptian pharaoh Necho II may have been the first to circumnavigate Africa around 610–595 BC. They reportedly saw the sun on their right while traveling clockwise, which modern historians see as evidence they understood Earth’s roundness. Historian Dmitri Panchenko suggests this voyage inspired the idea of a spherical Earth in the 5th century BC.
Ancient Greece
In ancient Greece, scholars like Strabo, Kish, and Dilke see Homer as the founder of early geographic thought, portraying Earth as a disk surrounded by the Ocean stream, an idea shaped by the horizon's appearance. This view was held by early Greeks who knew little beyond Egypt, Asia Minor, and the Black Sea, often through myth. Hesiod's poems from the 8th century BC show advanced knowledge of rivers like the Nile and Danube, and regions such as Sicily and Gaul. Anaximander of Miletus, pupil of Thales, made one of the first known world maps around 611–546 BC, imagining Earth as a cylindrical pillar with a circular disk-shaped habitable surface. His map, though lost, influenced Hecataeus of Miletus, who created another map fifty years later called Periodos Ges, dividing the world into Europe and Asia, using "days of sailing" or marching for measurement. He was the first to suggest the Caspian Sea flows into the ocean and placed the origin of the Nile at the southern ocean. His map, engraved on bronze, was carried to Sparta during the Ionian revolt. Anaximenes of Miletus later rejected the cylinder shape, proposing instead a rectangular Earth supported by air. Pythagoras speculated on a spherical Earth with a central fire, though the zonal theory of climate likely came from Aristotle. Scylax recorded Mediterranean voyages around 515 BC, creating early sailing instructions that influenced later mapmakers. Herodotus traveled widely, collecting knowledge about Europe, Asia, and Libya, combining it with what he learned from others, though no map by him has survived.
Hellenistic Mediterranean
Eratosthenes, a Greek scholar living in Hellenistic North Africa from 275 to 195 BC, calculated Earth's circumference with remarkable accuracy—within half a percent of today's measurement. As historian George Sarton noted, his contemporaries failed to recognize his genius, calling him "a man of genius" who worked in a new field. His works, including On the Measurement of the Earth and Geographica, survive only through later writers like Cleomedes and Strabo. He believed accurate maps required precise measurements and introduced meridians and parallels—north-south and west-east lines—based on Rhodes, dividing the world into sectors for precise location. Eratosthenes also proposed five climate zones: a central torrid zone, two frigid zones at the poles, and two temperate regions in between. He may have been the first to use the word "geography."
Pomponius Mela
Pomponius Mela, a geographer from the first century B.C., stood out among his ancient peers by proposing that the Earth was divided into five climate zones, with only two being habitable. He claimed that people lived in the northern and southern temperate regions, but that an area between them—what he called the torrid belt—was so blazingly hot it blocked access to a group he named the antichthones, who dwelt in the southern temperate zone. When it came to dividing Europe, Asia, and Africa, Mela followed the work of Eratosthenes. Like most classical geographers since Alexander the Great, he considered the Caspian Sea to be an inlet of the Northern Ocean, aligning it with the Persian Gulf and the Red Sea to the south.
Marinus of Tyre
Marinus of Tyre, a Hellenized Phoenician geographer and cartographer who lived around A.D. 70 to 130, founded mathematical geography and laid the groundwork for Ptolemy's influential Geographia. Though his own geographical treatise is lost, we know of his work through Ptolemy's remarks. He introduced improvements in mapmaking and developed a system of nautical charts, being the first to assign proper latitude and longitude to places. His zero meridian ran through the Isles of the Blessed near the Canaries, and he used the parallel of Rhodes for latitude measurements. He estimated the Earth's circumference at 33,300 kilometers—about 17% less than today's value—and was the first in the Roman Empire to map China. Marinus also invented the equirectangular projection still used today. Ptolemy recorded that Marinus believed the World Ocean was divided by Europe, Asia, and Africa, with the inhabited world stretching from Thule in Norway to Agisymba near the Tropic of Capricorn, and from the Isles of the Blessed to Shera in China. He coined the term Antarctic, referring to the region opposite the Arctic Circle.
Ptolemy
Ptolemy, a Hellenized Egyptian who lived from 90 to 168, believed astronomy and mathematics could help map the Earth with great accuracy. He changed how people viewed the globe by using perspective projection and introduced a system of latitude and longitude to locate places. His eight-volume work, Geographia, laid the foundation for modern maps and GIS, featuring an index of place-names with coordinates, scale, symbols with legends, and the practice of orienting maps so that north is up and east is to the right—a custom still used today. Yet Ptolemy made a major error: he miscalculated the Earth's circumference. He thought Eurasia took up 180 degrees of the globe, which led Christopher Columbus to attempt his voyage across the Atlantic, believing he could reach India more quickly by going west. Had Columbus known the true size of the Earth, it's possible he would never have set out.
Tabula Peutingeriana
In 2007, the Tabula Peutingeriana made its public debut after being placed on the UNESCO Memory of the World Register. This scroll, a 12th-century copy of a 5th-century Roman imperial road map, is considered an accurate reproduction of an original document. Though it has been well preserved, the fragile medium it is on now requires constant protection from daylight.
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Overview
A map in cartography shows the world and helps with navigation, science, government work, and war. People use them to plan routes, while special charts help sailors and pilots move safely. Scientists study weather and population using maps, while governments rely on them for counting people and managing police or disaster response. The oldest known map comes from the Akkadian Empire around 2300 BCE, carved into a clay tablet. By the 5th century BCE, the Greeks were making maps of their known world, including most of Europe, North Africa, and the Middle East. During the Age of Discovery, mariners used maps to explore new lands. In the late 1600s, thematic maps appeared showing specific data like rainfall or population density. With the growth of roads and public transit in the 20th century, mass-produced travel maps became popular. Then, in the mid-1900s, computers changed everything by making it possible to store and display huge amounts of geographic information. Interactive maps let users zoom, pan, and choose what data to see. Map design is complex, involving choices about what to show and how to organize elements like scale, projection, and coordinates.
Definition and etymology
The word "map" entered English around 1527 from Late Latin mappa meaning "napkin" or "cloth," or possibly French mappemonde or Latin mappa mundi, both translating to "map of the world." In cartography, early definitions described maps as representations of Earth printed on paper—like the 1938 definition by Erwin Raisz, who said it was "a conventionalized picture of the Earth's pattern as seen from above, to which lettering is added for identification." By the late 20th century, with computers and space exploration, definitions expanded. Arthur H. Robinson briefly defined a map in 1976 as "a graphic representation of the milieu," while John Brian Harley and David Woodward offered a 1987 definition that it was "graphic representations that facilitate a spatial understanding of things, concepts, conditions, processes, or events in the human world." Later still, a 1992 definition described maps as "a representation or abstraction of geographical reality: a tool for presenting geographical information in a way that is visual, digital or tactile." Outside of cartography, "map" has been used metaphorically, as the New English Dictionary noted in the 19th century, defining it as "a circumstantial account of a state of things," and the Oxford English Dictionary, as of 2026, includes both literal and figurative meanings.
Applications
Maps are used daily for navigation, finding points of interest like hospitals or restaurants, and planning trips. Travelers use road and tourist maps while air and sea traffic rely on specialized aeronautical and nautical charts for safe passage. Military and security forces depend on maps for surveillance and mission planning, and politicians use them for propaganda or international disputes. Governments employ maps for elections, taxation, urban planning, and managing utilities like water and electricity. Emergency services use them for evacuations and disaster response, while cadastral maps track property boundaries and zoning. Environmental managers monitor forests, wildlife, and climate change using maps, and scientists study geology, weather, and population spread through spatial data. Educators teach geography and history with maps, and journalists include them in reports to clarify geographic context. Digital maps enable autonomous vehicles and robots to navigate using localization and SLAM technologies.
Antiquity to 14th century
Maps appeared early in human history, with some of the oldest found in ancient cultures across the world. One of the earliest known maps is a clay tablet from 2300 BCE, discovered in Nuzi, part of the Akkadian Empire in modern-day Iraq. Egyptian papyrus maps from 1300 BCE show gold mine locations, and a Chinese document from 1020 BCE describes town planning maps. Early Chinese maps include a bronze sheet from the 4th century BCE showing mausoleum locations and silk maps from the 2nd century BCE that were more advanced than European ones of the time. In Greece, Hecataeus made a map around 490 BCE, while Ptolemy created an influential world map around 150 CE. The Romans used maps for administration; Julius Caesar commissioned one in 44 BCE by Agrippa, and the Tabula Peutingeriana depicted Roman roads schematically. In the Islamic world, Muhammad al-Idrisi made an atlas called Nuzhat al-Mushtaq in 1154 at the request of King Roger II. Medieval European maps, known as mappae mundi, often featured religious themes and were sometimes shaped like a "T" inside an "O," referred to as T-O maps.
15th to 19th centuries
Maps were crucial during the Age of Discovery. Christopher Columbus carried a map by Paolo dal Pozzo Toscanelli on his 1492 voyage, one that didn't show the Americas and underestimated the distance to Asia. Martin Behaim made the Erdapfel, one of the earliest globes, in the same era. In the 16th century, cartographers improved accuracy using triangulation, a method described by Gemma Frisius in 1533. Gerardus Mercator's 1569 projection became essential for sailors. Europeans also encountered indigenous maps used for navigation and trade. By the late 17th century, thematic maps showed data like rainfall or population. The 18th century saw major advances with accurate chronometers that allowed precise longitude calculations. Napoleon's geographic engineers in the late 18th century produced topographic maps for military use. As the 19th century progressed, maps helped shape national identity, as French historian Christian Jacob noted: "maps focused on individual nations were the visual glue of a sense of national identity."
20th century to present
During World War I, airplanes equipped with cameras flew over battlefields, taking photographs that were later used to update detailed trench maps as fine as 1:10,000 scale. Maps also became tools of propaganda, promoting territorial claims and inflating threats from enemies. As roads and transit systems expanded in the 20th century, there was a growing demand for mass-produced maps for travelers. The 1933 London Underground map introduced a new schematic style that prioritized usability over geographic accuracy. After WWI, cartographers began using aerial photos and photogrammetry to create maps faster than traditional ground surveys allowed. By the mid-1900s, cartography became more scientific and mathematical. Then, in the second half of the century, computers and satellites transformed the field through computer cartography and remote sensing. Geographic information systems, or GIS, enabled users to interact with geographic data on screens, zooming, panning, and selecting what to view.
Design
Map design is how cartographers decide what to show and how to show it, choosing what data to include or leave out, and deciding on things like scale, projection, orientation, and color. The mapmaker must consider the purpose of the map and who will use it. They select symbols, shapes, labels, and typography, all while working within a coordinate system. The legend helps readers understand what everything means, and the coverage area determines how much of the world is shown. A cartographer’s choices shape not just what’s on the page, but how people see space itself.
Layout and hierarchy
A map’s layout is about balance, according to cartographer Robinson, who describes it as “the process of arriving at proper balance,” where nothing feels too heavy or light, too long or short, or too close to the edge. Cynthia Brewer adds that good design uses visual hierarchy to show what's most important—like the title and main features—while less critical details go in the margins. She explains that key elements should appear in the foreground, while background ones recede, creating a figure-ground relationship. The basemap provides this context, including landforms, roads, or topography, helping readers understand the bigger picture.
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Overview
Cartography is the study and practice of making and using maps, blending science, aesthetics, and technique to model reality—whether real or imagined—in ways that effectively communicate spatial information. Traditional cartography aims to set a map’s agenda by selecting what traits to include, whether physical like roads or abstract like political boundaries. It must represent terrain on flat surfaces through map projections, while eliminating irrelevant details and reducing complexity through generalization. The final step is orchestrating all elements to best convey the intended message to the audience, a process known as map design. Modern cartography shares theoretical and practical roots with geographic information systems and geographic information science.
Ancient times
The earliest known map is hard to pin down, since the word "map" isn't clearly defined and some artifacts might not be maps at all. A wall painting from Çatalhöyük, dating to around 7000 BCE, may show the ancient city. Prehistoric rock carvings in France and Italy from the 4th millennium BCE feature geometric patterns that archaeologists interpret as cultivated plots. Among the oldest known maps are a Minoan painting from around 1600 BCE showing a seaside town and an engraved map of Babylon from the Kassite period, between the 14th and 12th centuries BCE. The oldest surviving world maps come from 9th century BCE Babylonia, one showing Babylon on the Euphrates surrounded by Assyria, Urartu, and other cities, all encircled by a "bitter river." The ancient Greeks and Romans made maps starting in the 6th century BCE; Ptolemy's 2nd-century CE treatise Geographia included his world map of the known Western world. Arab scholars translated Greek works into Arabic as early as the 8th century. Roman roads inspired itineraria, like the Tabula Peutingeriana, the only surviving example. In China, geographical texts date back to the 5th century BCE, with the oldest maps from the State of Qin in the 4th century BCE. Su Song's Xin Yi Xiang Fa Yao, published in 1092, contains a star map using equidistant cylindrical projection, possibly the oldest printed star chart. Ancient Indian cartography included depictions of the pole star and constellations, likely used for navigation.
Middle Ages and Renaissance
In the Middle Ages, European mapmakers created mappae mundi—world maps often found in manuscripts or as standalone documents. One of the most accurate was the Tabula Rogeriana, made by Arab geographer Muhammad al-Idrisi in 1154, combining classical and contemporary knowledge to produce a detailed world map and estimate of Earth's circumference. During the Age of Discovery, European cartographers like Martin Behaim and Martin Waldseemüller advanced mapping techniques, with Waldseemüller first using the name "America." Diogo Ribero created the first planisphere with a graduated equator, while Battista Agnese made at least 71 sea chart atlases. Johannes Werner introduced the Werner projection, and Gerardus Mercator developed his eponymous projection, also coining the term "atlas" for collections of maps. Abraham Ortelius published the first modern atlas, Theatrum Orbis Terrarum, crediting 183 contributors by 1603. Maps in the Renaissance served to display power, guide navigation, and manage land, becoming symbols of education and sophistication.
Printing technology
In the Renaissance, mapmakers used two main printmaking methods: woodcut and copper-plate intaglio, which referred to the medium used to transfer the image onto paper. With woodcut, the map was carved into medium-grain hardwood, with raised lines inked and pressed against paper, leaving indentations that could be felt on the back. Though the technique allowed for rubbings and didn't require a press, it lacked fine detail and could produce inconsistencies over time. By the late fifteenth century, craftsmen began using finer chisels to improve quality. In intaglio, lines were etched into copper or brass plates, with ink left only in the grooves after scraping. The plate was then pressed forcefully against paper, creating a distinctive plate mark around the edge. Because metals were expensive, plates were often reused or melted down. Both methods were used about equally by the end of the fifteenth century, and maps were dried and flattened in a second press using whatever paper was available, though thicker paper was more durable.
Lettering
Lettering on maps plays a key role in sharing information, but it was especially tricky when makers worked with woodcuts, where the text often ended up looking square and blocky—quite the opposite of the flowing, rounded style that was popular in Italy at the time. To make their letters clearer and more elegant, mapmakers began using finer chisels to carve the wood more precisely. Intaglio printing avoided many of these problems, allowing for the kind of looping cursive writing known as cancellaresca. Some mapmakers also used custom-made reverse punches along with freehand techniques in metal engraving to get just the right look.
Color
The first use of color in map-making has no single cause. Some say it began to show information, with beauty coming later. Others believe aesthetics came first, then function. During the Renaissance, many maps were published without color, a practice that lasted well into the 1800s. Still, if patrons wanted their maps colored, publishers would oblige. The cost depended on the design—simple outlines, washes of ink or watercolor, or even gold and silver leaf for more elaborate work. Limning added shimmer to lettering or heraldic details, while wash color filled in regions. Patrons could choose how much they wished to spend, from basic coloring to expensive gilding.
Early modern period
In the early modern period, mapmaking techniques spread across Eurasia, especially through trade routes in the Indian Ocean. Around 1620, a Chinese cartographer created the Selden map, challenging the idea that East Asia didn’t do mapping before Europeans arrived. It showed trading paths, a compass rose, and a scale bar, showing how Chinese mercantile traditions had developed advanced methods. Then in 1689, Russian and Qing representatives met near Nerchinsk to negotiate borders. The Qing brought Jesuit intermediaries, and they agreed on the Amur River as the dividing line, opening trade between the two powers.
Age of Enlightenment
During the Age of Enlightenment, mapmakers moved away from fragile woodcuts to the stronger copper plate intaglio method, and new projections like the Mercator chart began showing up more often for navigation. But with little reliable data and surveying still extremely hard, many cartographers reused work without giving credit. A famous case is the “Beaver Map,” published in 1715 by Herman Moll, which was nearly identical to a 1698 version by Nicolas de Fer. De Fer had in turn copied images first found in books by Louis Hennepin, printed in 1697, and François Du Creux, published in 1664. By the end of the 18th century, some mapmakers started including phrases like “After [the original cartographer]” in their titles or cartouches to acknowledge earlier sources.
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Description
In the early 15th century, Europe had no printing press and knew little of the Western Hemisphere, yet it still produced navigational charts for sailors and scholarly texts for those with money to spend. One such text is Harley MS 3686, held today at the British Library. This codex was copied in the 1400s from an all-Latin version of Ptolemy’s Geographia, based on one of the rare reprints that included map sheets. Most other copies only had text, and scholars have long found it nearly impossible to recreate the maps just from Ptolemy’s written instructions. Despite its geographic focus and visual appeal, this manuscript has received little scholarly attention—so much so that even major surveys like Nordenskiöld’s Facsimile Atlas and Father Joseph Fisher’s Claudii Ptolemaei Geographiae Codex Urbinas Graecus leave it out.
Scribe
The scribe of Harley MS 3686 was likely a mapmaker, judging by hand-drawn quality and Latin spelling mistakes showing limited fluency. Drawing from sources like Pliny and Andrea Bianco's 1436 Ptolemaic codex, this unknown cartographer was probably from Venice, based on similarities to Bianco's work and use of Venetian mapmaking traditions. Scholars in Florence were humanists who didn't use the same systems, and neither did those in Genoa or Naples. The scribe improved upon Ptolemy's maps, cross-referencing ancient Latin names with modern ones, and added places unknown in Ptolemy's time, like areas around the Caspian Sea. He updated some projections, refining Ptolemy's equi-rectangular and orthographic methods but before the Mercator projection was published. His work focused on regional maps of Europe, North Africa, and the Levant, outperforming later codices such as the 1459 Mappa Mundi by Venetian monk Mauro or the 1481 Wilczek-Brown Codex.
Provenance
Robert Burscough was one of the manuscript’s earlier owners, though the exact path from Venice to England remains uncertain, likely involving maritime trade between the Mediterranean and North Sea during the 15th or 16th centuries. After Burscough's death, his widow auctioned the book in May 1715 to Robert Harley, who was then a member of Parliament and a collector of rare books. MS 3686 entered Harley’s private library, and the collection stayed within the family for generations. In 1753, Margaret Bentinck, Duchess of Portland, sold the entire set to the British Government.
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Overview
The 2020 United States redistricting cycle happened after the census counted the population, and every state had to redraw its legislative districts. States with more than one seat in Congress also had to create new congressional maps. Each state uses different rules, sometimes having the legislature or a special commission do the work, or a mix of both. Even though there are laws and court decisions trying to limit it, many redistricting bodies still practice gerrymandering, which means drawing districts to help one political group. Political parties get ready years ahead of time, and whoever controls the redistricting process can gain a big edge. The maps from 2020 will stay in place until the next round after the 2030 census.
Reapportionment
The United States Constitution's Article One requires the House of Representatives to be divided among states based on population, with reapportionment every ten years after the census. Since 1929, Congress has followed this rule using the Huntington-Hill method to assign the 385 seats remaining after each state gets at least one. The number of representatives has stayed at 435 since 1913, though it rose briefly in 1959. Reapportionment also changes how many electoral votes each state gets for presidential elections. After the 2020 census, states like California, Illinois, Michigan, New York, Ohio, Pennsylvania, and West Virginia each lost one seat, while Colorado, Florida, Montana, North Carolina, and Oregon each gained one, and Texas gained two. For the first time in its history, California lost a seat, continuing a trend of Northeastern and Midwestern states losing population-based representation to Western and Southern ones.
Congressional redistricting methods
After each census, states with more than one congressional district must redraw voting maps before the next election. Most states let their legislatures draw lines, but some use independent commissions—like Arizona, California, Colorado, Idaho, Michigan, and Washington. Hawaii and New Jersey have "politician commissions." Alaska, Delaware, North Dakota, South Dakota, Vermont, and Wyoming won't redraw lines because they each have only one representative. In most states, legislatures draw districts to help their own party, a practice known as gerrymandering. Some states require special votes—like Connecticut and Maine needing two-thirds majorities—while others let governors veto plans unless overridden by a simple majority, as in Alabama, Indiana, Kentucky, Tennessee, and West Virginia. In Ohio, the process encourages bipartisan support, but the majority party can still push through a map for four years without minority approval.
Limits on congressional redistricting
Though states have wide latitude in redrawing congressional districts, their power is limited by the U.S. Constitution, federal court rulings, and laws passed by Congress. In Wesberry v. Sanders, the Supreme Court ruled that districts must be equal in population “as nearly as is practicable.” Subsequent cases required states to redistrict every ten years, though some do so more often under their own rules. The Uniform Congressional District Act of 1967 barred most states from using multi-member districts, requiring single-member ones instead. The Voting Rights Act of 1965 protects minority voters from discriminatory redistricting, and the Supreme Court case Thornburg v. Gingles set a test for determining violations. In some states, courts have mandated majority-minority districts. Many states also adopt additional standards, like compactness or preserving cities and communities of interest. Some, including Arizona, Colorado, New York, and Washington, require competitive districts.
Congressional redistricting plans passed by legislature
In the 2020 United States redistricting cycle, state legislatures crafted congressional maps with varying degrees of partisan control and legislative power. Some states allowed governors to veto bills, but those vetoes could be overridden by a simple majority of the legislature. Others required a two-thirds supermajority for overrides, marked by a "*". In Ohio, specific qualified majorities were needed at each stage of the redistricting process to ensure maps would stand up to judicial review for the full decade. A few states used advisory or backup commissions to guide their redistricting efforts, indicated by "†" and "‡". These processes shaped how borders were drawn and, ultimately, how political power was distributed across the nation.
Congressional redistricting plans passed by commissions
In 2020, five states used independent commissions to draw congressional districts. Arizona, Montana, and Washington each had four party leaders select one member of the Independent Redistricting Commission, with those four choosing a fifth unaffiliated member. California's Citizen's Redistricting Commission originally had five Democrats, five Republicans, and four nonpartisan members, though that changed after Proposition 50 passed. Idaho's Commission for Reapportionment was chosen by four party leaders from the state house and senate and chairmen of the two most popular parties based on the latest gubernatorial vote. Hawaii's Reapportionment Commission had members selected by the president of the state senate, the speaker of the state house, and minority party leaders in both chambers, with eight appointed members choosing a ninth to chair the commission. New Jersey's Apportionment Commission was made up of members chosen by four party leaders from the state house and senate and the leaders of the two largest parties, with twelve members selecting a thirteenth to chair the commission. Virginia used a hybrid, bipartisan commission with eight legislators and eight non-legislator citizens evenly divided between Democrats and Republicans. Ohio had a hybrid commission as a backup authority in case the legislature failed to approve a redistricting plan with a qualified majority; if that happened, the state legislature would then pass the plan either for the full decade via a qualified majority or for four years through normal legislative procedure.
Legislative redistricting methods
Every ten years, states redraw legislative district boundaries, with Nebraska being the exception for having a non-partisan legislature. Most states must finish their redistricting plans by the 2022 election deadlines, though Virginia and New Jersey have 2021 deadlines, Louisiana and Mississippi have 2023, and Montana has 2024. Fifteen states use independent or politician commissions for this task, while in the others, the legislature itself is responsible, sometimes with advisory or backup commissions. Connecticut, Illinois, Mississippi, Oklahoma, and Texas have backup commissions that step in if the legislature fails to agree. Iowa, Maine, New York, Rhode Island, and Vermont use only advisory commissions. In Oregon, the Secretary of State draws districts if needed, and in Connecticut and Maine, a 2/3 super-majority is required. In Connecticut, Florida, Maryland, Mississippi, and North Carolina, governors cannot veto redistricting plans. Alabama, Indiana, Kentucky, Tennessee, and West Virginia allow legislatures to override gubernatorial vetoes with simple majorities, giving those governors little influence in the process.
Limits on state legislative redistricting
In the United States, states have broad power to redraw legislative districts, but the Supreme Court case Reynolds v. Sims set a key rule: districts must be “substantially equal” in population. Federal courts have further required that the difference between the largest and smallest districts not exceed ten percent, with some states setting stricter limits. The Voting Rights Act of 1965 protects against racial gerrymandering that would block minority voters from electing chosen representatives. The Supreme Court’s Thornburg v. Gingles case created a test to determine if redistricting violates that law. States also often follow additional guidelines like compactness, keeping counties or cities together, and preserving communities of interest. Some states, such as Arizona, require competitive districts, while others mandate nesting state house districts within state senate districts.
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Overview
In 2026, Americans will head to the polls on November 3 for midterm elections taking place during Republican President Donald Trump’s nonconsecutive second term. All 435 U.S. House seats and 35 Senate positions will be up for election, determining the 120th United States Congress. Alongside those contests, 39 state and territorial gubernatorial races, attorney general elections, and numerous local votes will also occur. These elections come amid federal investigations into the 2020 presidential vote and voter registration activities, including the removal of ballots from the Fulton County, Georgia, election center and a search of the Ohio Organizing Collaborative’s offices by the FBI. Election experts and Democratic officials have called these actions efforts to intimidate election workers and voters, while the Justice Department has stated the searches were court-authorized.
Background and campaign
In 2024, Donald Trump defeated Kamala Harris in a tight presidential election shaped by post-pandemic recovery, rising inflation, and foreign policy challenges like the Russo-Ukrainian and Israel-Hamas conflicts. His second administration introduced sweeping tariffs to re-industrialize the U.S., a plan criticized for worsening inflation and drawing global criticism. Immigration policies, including increased deportations under the One Big Beautiful Bill Act, also sparked controversy. The outbreak of war with Iran in February 2026 intensified economic strain, with gas prices becoming a central issue for voters. Analysts said fuel costs were a key political driver behind Trump's push for a ceasefire before the midterms. For the first time since 2016, major news outlets used one election survey, The Voter Poll by SSRS, to track public opinion in 2026. Though not running again, Trump's approval remains a factor, as exit polls from 2025 showed many voters opposed him, and surveys found declining support for his economic and immigration policies. In November 2025, Republicans underperformed, with Democrats winning gubernatorial races in Virginia and New Jersey by larger margins than expected. Zohran Mamdani, a self-identified democratic socialist, was elected mayor of New York City in a three-way race. The overarching theme of the 2025 off-year elections was the United States affordability crisis.
Allegations of attempted election subversion
In January 2026, The Washington Post revealed the second Trump administration was using tactics like redrawing congressional districts for political advantage, going after opponents through prosecution, and pushing changes to voting rules to erode trust in midterm elections. Trump suggested canceling the vote, pointing to a likely loss and lack of faith in democracy; White House Press Secretary Karoline Leavitt clarified he was "speaking facetiously." By February, Trump proposed nationalizing elections to stop fraud, while Steve Bannon claimed ICE would be sent to poll watching to prevent a Democratic win. The House passed the SAVE America Act requiring proof of citizenship to register, though it failed in the Senate that June. The Justice Department demanded voter data from 23 states—mostly led by Democrats or who voted for Biden in 2020—and a federal judge dismissed a lawsuit against California, calling the request a privacy violation and a "chilling effect." The department appealed while launching investigations into several states' election systems, including Georgia, Michigan, and Wisconsin. In June, FBI agents searched the offices of a voter registration group in Ohio as part of a broader federal push targeting voting infrastructure ahead of the elections.
Senate elections
In the 2026 United States Senate elections, 35 seats will be up for grabs, including all 33 Class 2 seats. The Republicans gained control of the Senate in 2024 by flipping four Democratic seats. Two of the remaining Democratic-held seats are in states that Donald Trump won in the previous presidential election: Georgia and Michigan. Maine is the only Republican-held seat in a state that Kamala Harris won.
House of Representatives elections
In the 2026 United States elections, all 435 seats in the House of Representatives will be up for grabs, along with races for the non-voting delegate for the District of Columbia and delegates from four of the five U.S. territories, Puerto Rico excluded due to its delegate’s four-year term. There are 16 Democratic incumbents in districts that Donald Trump won, while only eight Republican incumbents are in seats that Kamala Harris carried. The House map includes several new congressional districts: Ohio and Utah will have court-mandated maps this cycle; Missouri, North Carolina, and Texas redrew their maps mid-term; and California changed its district boundaries after Prop 50 passed.
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Overview
Pennsylvania’s 12th congressional district now includes all of Pittsburgh and most of Allegheny County, along with parts of Westmoreland County. Summer Lee has represented it since January 3, 2023. Before 2018, the district stretched across Beaver County and into several other areas. That year, the Pennsylvania Supreme Court ordered new maps after ruling the old one unconstitutional due to partisan gerrymandering. The updated 12th district absorbed much of what had been the 10th district’s territory. The former 12th became the 17th district for 2018 elections onward. Prior to the 2011 redistricting, the 12th was considered a heavily Democratic district drawn by the Republican-controlled legislature, and it encompassed Greene County and portions of Allegheny, Armstrong, Cambria, Fayette, Indiana, Somerset, Washington, and Westmoreland Counties.
History
After the 2000 census, Pennsylvania's Republican-controlled legislature redrew congressional districts favoring Republicans, especially in southwestern areas once solidly Democratic. The 12th district was created by merging parts of the old 20th with new territory, including all of Greene County and significant portions of Allegheny, Armstrong, Cambria, Fayette, Indiana, Somerset, Washington, and Westmoreland Counties. This included heavily unionized regions like the Monongahela Valley and coal-mining areas centered around Johnstown, as well as suburbs such as New Kensington and Lower Burrell. The district also contained parts of Washington County, including the city of Washington and eastern areas, while western portions went to the 18th district. Notably, it was one of only two districts in the nation to vote for Democratic presidential candidate John Kerry in 2004 but support Republican John McCain in 2008—a shift reflecting broader changes in southwestern Pennsylvania's political leanings since 2000.
2010 special election
After Representative John Murtha died, Pennsylvania governor Ed Rendell called a special election for May 18, 2010, to fill his seat. The Democratic Party’s executive committee chose Mark Critz, who had been Murtha’s district director, to represent them in the race. On the Republican side, Tim Burns, a businessman from the 12th congressional district, was nominated at a local convention. The Libertarian Party picked Demo Agoris, who had previously run for the Pennsylvania House of Representatives in the 48th district. Mark Critz ultimately won the election.
2012 election
In the 2012 election, Mark Critz sought a second full term in Pennsylvania's 12th congressional district but lost to Republican Keith Rothfus. Critz received 48.5% of the vote, while Rothfus took 51.5%. The district had changed significantly after the 2010 census, absorbing much of the former 4th district, including Rothfus’s hometown. As a result, the 12th had become notably more Republican than before.
Counties and municipalities
In Pennsylvania’s 12th congressional district, Allegheny County includes forty-six municipalities, from Baldwin to Wilmerding, with Pittsburgh at its heart, and parts of seventeen counties in Westmoreland, like Adamsburg and Trafford, which also stretches into Allegheny. Some places, like Hempfield Township and South Huntingdon Township, are split between districts, while others, such as Turtle Creek and Swissvale, appear in both counties. The boundaries of these areas reflect the complex history of how maps shaped local identity, drawing lines through neighborhoods, towns, and even shared territories, like Trafford, which belongs to both counties. These names mark not just geography but the stories of people who lived within them, their struggles, and their communities.
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Overview
Tennessee, a landlocked Southeast state bordered by eight neighbors and home to about 7.22 million people as of 2024, is divided into three regions—East, Middle, and West Tennessee—with Nashville anchoring the largest metropolitan area. Its landscape varies from Blue Ridge Mountains in the east to flat western plains, with the Tennessee and Mississippi Rivers running through it. The Watauga Association, formed in 1772, is seen as the first constitutional government west of the Appalachian Mountains, and the state's name comes from the Cherokee town Tanasi. It became the 16th state on June 1, 1796, earning the nickname "The Volunteer State." During the Civil War, it was a slave state divided politically, seceding last and rejoining first after Reconstruction. In the 20th century, federal investment in the Tennessee Valley Authority and Oak Ridge helped shift its economy from farming to industry, including science and music, which it helped shape.
Etymology
The name Tennessee comes from the Cherokee town of Tanasi, located in present-day Monroe County on the Little Tennessee River. In 1567, Spanish explorer Captain Juan Pardo encountered a village named “Tanasqui” nearby, though it's unclear if that was the same settlement. The name appeared on British maps as early as 1725. Recent research suggests the Cherokees adapted it from the Yuchi word Tana-tsee-dgee, meaning “brother-waters-place” or “where-the-waters-meet.” Governor James Glen of South Carolina used the spelling “Tennessee” in official correspondence during the 1750s. In 1788, North Carolina created “Tennessee County,” and in 1796, the new state’s constitutional convention chose “Tennessee” as its name.
Pre-European era
The earliest people in Tennessee were Paleo-Indians who reached the area about 12,000 years ago at the end of the Ice Age. Hunter-gatherers lived in the lower Tennessee Valley, and Middle Tennessee was rich with animals like mastodons. Archaeologists have identified cultural periods including the Archaic, Woodland, and Mississippian eras. During the Archaic period, people first domesticated dogs, and in the Woodland era, crops such as corn and squash were grown. Woodland peoples also built the first mounds. By the Mississippian time, Indigenous communities had formed chiefdoms and constructed many ceremonial structures. Spanish explorers in the 1500s encountered groups like the Muscogee Creek, Yuchi, and Shawnee. By the early 1700s, most Native people had died from diseases brought by Europeans. In the late 1600s, the Cherokee began moving into eastern Tennessee from Virginia, possibly to escape settlers and illness. They pushed out other groups such as the Creek, Yuchi, and Shawnee. The Chickasaw remained in West Tennessee, while much of central Tennessee had few Native Americans, though both the Cherokee and Shawnee claimed the region for hunting. European settlers called the Cherokee living west of the Blue Ridge Mountains the Overhill Cherokee, and their settlements grew along rivers in East Tennessee during the early 1700s.
Exploration and colonization
Spanish explorers entered Tennessee in the mid-1500s, with Hernando de Soto (1540–1541), Tristan de Luna (1559), and Juan Pardo (1566–1567). English trader Abraham Wood sent an expedition in 1673; French explorers Jacques Marquette and Louis Jolliet mapped the Mississippi in 1673. René-Robert Cavelier, Sieur de La Salle, built Fort Prudhomme in West Tennessee in 1682. French traders explored the Cumberland River by the late 1600s, and in 1714, Charles Charleville’s forces established French Lick near present-day Nashville. In 1739, Jean-Baptiste Le Moyne de Bienville led Fort Assumption on the Mississippi at modern Memphis to fight the Chickasaw. Longhunters from Virginia explored East and Middle Tennessee in the 1750s–1760s. Settlers built Fort Loudoun in 1756, the first British outpost west of the Appalachians, sparking conflict with the Cherokees. After the French and Indian War, Britain’s Royal Proclamation of 1763 banned settlements west of the mountains, but migration continued. In the late 1760s, English and Scotch-Irish settlers arrived in northeastern Tennessee, forming the Watauga Association in 1772 and later the Washington District. Richard Henderson negotiated treaties with the Cherokee in 1775, selling land for the Transylvania Colony. Daniel Boone blazed the Wilderness Road through the Cumberland Gap. Dragging Canoe, a Cherokee leader, opposed the settlements and attacked Fort Watauga in 1776. In 1779, settlers from the Washington District founded Fort Nashborough, later Nashville. The next year, they signed the Cumberland Compact, forming the Cumberland Association. In 1784, three counties of the Washington District broke off to form the State of Franklin, but it never joined the Union. By 1788, those counties rejoined North Carolina, which ceded the area to the federal government in 1790, creating the Southwest Territory. William Blount became territorial governor, and the territory’s population reached 35,691 in the first U.S. census that year, including 3,417 slaves.
Statehood and antebellum era
Tennessee became the 16th state on June 1, 1796, following elections in 1793 and a constitutional convention where the name "Tennessee" was chosen. The state's first governor was John Sevier, and it was the first state formed from federal territory. During the War of 1812, Tennesseans earned the nickname "The Volunteer State" when 3,500 soldiers joined Andrew Jackson's command, helping secure a major victory at the Battle of New Orleans in 1815. Later, during the Mexican-American War, more than 30,000 volunteers answered President Polk's call. Land cessions with Native American tribes included the "Jackson Purchase" in 1818, and the forced removal of the Cherokee in 1838 and 1839 became known as the Trail of Tears. Slavery grew in West Tennessee after the Jackson Purchase, while East Tennessee developed an early abolition movement, with Elihu Embree publishing the first anti-slavery newspaper in the nation in 1819.
Civil War
At the start of the Civil War, most people in Middle and West Tennessee supported preserving slavery but were unsure about leaving the Union; in East Tennessee, most favored staying with the United States. In 1860, slaves made up about 25% of Tennessee’s population, the lowest among Confederate states. After Lincoln’s election, Governor Isham Harris led efforts to secede, which was rejected in a referendum by a 54–46% margin in February 1861. After the attack on Fort Sumter and Lincoln's call for troops, the legislature agreed to join the Confederacy on May 7, 1861. On June 8, Middle Tennesseans voted to secede by a 69–31% margin, making Tennessee the last state to do so. East Tennessee Unionists formed a convention in Knoxville aiming to split off and create a new Union state. Guerrillas burned bridges and attacked Confederate sympathizers, prompting martial law in parts of the region. Many southern unionists fled to Kentucky, while others either resisted or eventually joined the Confederacy. In March 1862, Lincoln appointed Andrew Johnson as military governor of Tennessee. Ulysses S. Grant captured the Tennessee and Cumberland rivers at Fort Henry and Fort Donelson in February 1862. At Shiloh in April, Grant held off a Confederate counterattack, which became the bloodiest battle of the war so far. Memphis fell to Union forces in June after a naval battle on the Mississippi River. Union strength in Middle Tennessee was tested by Confederate offensives beginning in summer 1862, culminating in the Battle of Stones River where Grant’s army defeated Bragg’s. The next summer, Rosecrans's Tullahoma campaign forced Bragg’s troops to retreat to Chattanooga. During the Chattanooga campaign, Confederates tried to take the city but were driven out by reinforcements under Grant, Sherman, and Hooker at Lookout Mountain and Missionary Ridge in November 1863. Despite Unionist sentiment in East Tennessee, Confederate forces held the area for most of the war. Shortly after Chattanooga’s fall, James Longstreet led an unsuccessful campaign to capture Knoxville. The Union victory at Chattanooga allowed Sherman to begin his Atlanta campaign in May 1864. In the fall of 1864, John Bell Hood invaded Middle Tennessee, but was stopped by John Schofield at Franklin and completely defeated by George Thomas at Nashville in December. On April 27, 1865, the Sultana steamboat exploded in the Mississippi River north of Memphis, killing 1,168 people. When Lincoln issued the Emancipation Proclamation, Tennessee was largely under Union control, so it didn’t officially free any slaves there. Johnson declared all slaves in Tennessee free on October 24, 1864. On February 22, 1865, the state legislature approved an amendment to ban slavery, which voters accepted the following month. This made Tennessee the only Southern state to abolish slavery at that time. Tennessee ratified the Thirteenth Amendment on April 7, 1865. On July 18, 1866, it became the first Confederate state to ratify the Fourteenth Amendment, granting citizenship and equal rights to former slaves. Both amendments went into effect after Tennessee’s readmission to the Union because other states hadn’t yet ratified them. After Lincoln’s assassination in May 1865, Johnson became president. On July 24, 1866, Tennessee became the first Confederate state to have its elected members readmitted to Congress.
Reconstruction and late 19th century
After the Civil War, Tennessee experienced tension between Black citizens and former Confederates, especially in Memphis in 1866. Because Tennessee had ratified the Fourteenth Amendment before rejoining the Union, it was the only former Confederate state without a military governor during Reconstruction. Federal troops stayed on to protect property and enforce laws. Radical Republicans took control of the state government, appointing William G. "Parson" Brownlow as governor. Under his leadership from 1865 to 1869, African American men were allowed to vote, former Confederates were disenfranchised, and martial law was used against the Ku Klux Klan, formed in December 1865 in Pulaski. By 1870, Southern Democrats reclaimed control of the legislature and began passing Jim Crow laws. Over the next two decades, they enforced racial segregation, and 251 lynchings—mostly of Black people—occurred in Tennessee. Epidemics like cholera in 1873 and yellow fever in 1878 struck hard, especially in Nashville and Memphis. Reformers worked to modernize the state into a "New South" economy. Chattanooga industrialized early with Northern investment, while Memphis became known as the "Cotton Capital of the World." Nashville, Knoxville, and other cities saw modest growth. Northerners also began exploiting coalfields and mineral resources in the Appalachians. To pay off debts and ease prison overcrowding, the state leased prisoners to mining companies, sparking protests. An armed uprising called the Coal Creek War in 1891 and 1892 led to the end of convict leasing. Despite these efforts, agriculture remained dominant, and most freed slaves were forced into sharecropping or wage labor. In 1897, Tennessee celebrated its centennial with the Tennessee Centennial and International Exposition in Nashville, featuring a full-scale replica of the Parthenon designed by architect William Crawford Smith.
Early 20th century
In the early 1900s, Tennessee saw major shifts as Black residents left rural areas for Northern cities during the Great Migration, and many others moved to urban centers within the state for work. The Temperance movement led Tennessee to become the first state to ban alcohol, sparking a rise in moonshine production, especially in East Tennessee. Sgt. Alvin C. York became a hero of World War I, earning the Medal of Honor. A tragic train crash in Nashville killed over 100 in 1918. Tennessee ratified the Nineteenth Amendment in 1920, granting women voting rights. In 1925, John T. Scopes was convicted for teaching evolution, drawing national attention to the debate between creationism and science. Congress authorized a national park in the Great Smoky Mountains in 1926, later dedicated in 1940. During the Depression, the Tennessee Valley Authority brought electricity and jobs, though it displaced families through eminent domain. During WWII, East Tennessee was chosen for the Manhattan Project; Oak Ridge was built to produce uranium for atomic weapons, including the bomb dropped on Japan, and afterward, the Oak Ridge National Laboratory became a center for scientific research.
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