The Museum of Everyday Living · Transportation · Education
Maps that made the world
Every map is an argument: what to show, what to leave out, and what to stretch
SI painting, made for this explainer: an illustration, not a photograph.
A map is the oldest data visualization and the most trusted. That trust is the reason to read maps closely. A clay tablet put Babylon at the center of the world; a Roman road map flattened an empire into a travel strip; Mercator stretched the poles so sailors could steer; a doctor in London used dots to find a deadly pump; a federal agency colored neighborhoods red and shaped who could buy a home. Today the same habits live inside GPS and GIS, the tools behind the city research on this estate.
Part oneThe first maps: the world as people believed it
c. 600 BCE · Sippar, Iraq (British Museum)
The Babylonian map of the world
A small clay tablet showing Babylon on the Euphrates inside a ring of "bitter river", the ocean, with triangles for distant regions beyond. It is a map of belief as much as of land: the known world at the center, the unknown at the edge.
Figures marked ≈ or "about" are estimates or disputed.
Osama Shukir Muhammed Amin FRCP(Glasg) (Wikimedia Commons) · CC BY-SA 4.0
c. 150 CE · Alexandria
Ptolemy's Geography
Claudius Ptolemy listed about 8,000 places by latitude and longitude and explained how to draw a curved earth on flat sheets. His book returned to Europe around 1400 and was printed with maps from 1477; it taught mapmakers to use a grid.
13th-century copy of a 4th–5th century map · Austrian National Library, Vienna
The Tabula Peutingeriana: a Roman road map
A strip about 6.7 m long and 34 cm high that squeezes the Roman Empire into a long band of roads, towns, baths and distances, like a subway map. It cares about travel, not shape. See the roads room in Rome: how they built it.
A map carved on a stone stele with a grid of squares, each about 100 li (roughly 50 km), and a coastline and river system of startling accuracy for its time. China used grids and scale centuries before Europe did again.
Figures marked ≈ or "about" are estimates or disputed.
Édouard Chavannes (Wikimedia Commons) · Public domain
1154 · Palermo, Sicily
Al-Idrisi's Tabula Rogeriana
Made for the Norman king Roger II by the scholar Muhammad al-Idrisi from travelers' reports. South is at the top, as on many Islamic maps. It was the most accurate world map in the Mediterranean for about three centuries.
The Roman road map belongs with the roads themselves: see the roads room in Rome: how they built it.
Part twoMaps for faith and maps for sailors
c. 1300 · Hereford Cathedral, England
The Hereford Mappa Mundi
East at the top, Jerusalem at the center, Paradise at the edge, monsters at the margins. A map for teaching history and faith on a cathedral wall, not for finding the road to London.
Unknown authorUnknown author (Wikimedia Commons) · Public domain
from c. 1275 · Mediterranean ports
Portolan charts
Sea charts drawn from sailors' compass bearings, crossed by webs of rhumb lines radiating from compass roses. The Carta Pisana (about 1275) is the oldest surviving. Coastlines suddenly look right because people measured them from ships.
Figures marked ≈ or "about" are estimates or disputed.
Unknown authorUnknown author (Wikimedia Commons) · Public domain
Part threeA new world and the projection problem
1507 · Saint-Dié, France (Library of Congress)
Waldseemüller names America
Martin Waldseemüller's world map is the first to print the name "America", after Amerigo Vespucci. The only surviving copy was bought by the Library of Congress in 2003 for $10 million.
Martin Waldseemüller (Wikimedia Commons) · Public domain
1569 · Duisburg
Mercator's projection
Gerardus Mercator stretched the map toward the poles so that any straight line is a constant compass course, perfect for navigators. The price is size: Greenland looks as big as Africa, which is about 14 times larger. Try the projection switcher below.
Gerardus Mercator (Wikimedia Commons) · Public domain
1855, 1973 · Europe
Equal-area maps and the Peters argument
James Gall drew an equal-area map in 1855; Arno Peters promoted a near copy in 1973 as fairer to the Global South. Cartographers answered that every flat map distorts something, and offered compromises like the Robinson (1963) and the Winkel tripel, used by National Geographic since 1998.
You cannot flatten an orange peel without tearing or stretching it, and you cannot flatten the earth without distorting shapes, sizes, distances or directions. Switch the projection and watch Greenland and Africa.
Loading the map…
Country outlines: Natural Earth via world-atlas (public domain). Antarctica is left off because Mercator cannot show the poles at all. True areas: Africa about 30.4 million km², Greenland about 2.17 million km², so Africa is about 14 times larger.
Go deeper
Lessons:E38 4 · The projection claimPreviewE38 6 · The Mercator wall mapPreviewE38 2 · Latitude and longitudePreview
SI painting, made for this explainer: an illustration, not a photograph.
1750s–1815 · France
The Cassini map of France
Four generations of the Cassini family built the first national map from a chain of measured triangles across the whole country. Triangulation turned mapmaking from sketching into measurement.
Begun by William Lambton in 1802 and carried on by George Everest, it measured India with giant theodolites over decades. Its computers found that Peak XV was the highest in the world, named Mount Everest in 1865; the local names Chomolungma and Sagarmatha are older.
SI painting made for this explainer (Artlist, GPT Image 2.5) · illustration
Part fiveMaps as evidence, and maps as harm
In the 1800s mapmakers began to map people, illness and money, not just land. These maps changed public health and sociology. One of them, the redlining map, did lasting damage.
1854 · Soho, London
John Snow's cholera map
Snow marked each cholera death as a bar on a street map and saw them cluster around the Broad Street water pump. The map helped argue that cholera spread through water, not bad air. A founding picture of epidemiology and of spatial analysis.
Booth's researchers walked every street and colored it from black ("lowest class") to gold ("wealthy"). The map showed rich and poor streets side by side, a founding model for urban sociology and for the city research on this estate.
Charles Joseph Minard drew Napoleon's 1812 army as a band whose width shrinks with every loss on the way to Moscow and back, with temperature below. Often called one of the best statistical graphics ever drawn.
Charles Minard (1781–1870) (Wikimedia Commons) · Public domain
1935–1940 · US cities
Redlining maps
The federal Home Owners' Loan Corporation graded neighborhoods for mortgage risk, coloring many Black and immigrant areas red as "hazardous". The maps shaped lending for decades. The University of Richmond's Mapping Inequality project puts them online.
Every state taxes gasoline. Here is the 2025 state gas tax in cents a gallon, one tile per state. Change only the class breaks and the colors; the numbers never change. Watch the headline a reporter might write.
Data: Federation of Tax Administrators, State Motor Fuel Tax Rates (2025), excise tax only. The same table drives Two Seasons. Idea from Mark Monmonier, How to Lie with Maps.
Part sixFrom the paper quad to the phone in your pocket
SI painting, made for this explainer: an illustration, not a photograph.
from 1879 · United States
The USGS topographic map
The U.S. Geological Survey has mapped the country since 1879; its 7.5-minute quadrangles at 1:24,000 show contour lines, streams and roads. The maps are public domain, so they appear in the mini-GIS below.
The Global Positioning System launched its first satellite in 1978 and reached full operation in 1995. When the U.S. switched off the deliberate error ("Selective Availability") in May 2000, every phone could soon locate itself within a few metres.
Roger Tomlinson's Canada Geographic Information System of the 1960s stored maps as data layers a computer could overlay and measure. Esri was founded in 1969. GIS is how the research on this estate maps cities, buildings and transit.
SI painting made for this explainer (Artlist, GPT Image 2.5) · illustration
2004 · worldwide
OpenStreetMap
Steve Coast started OpenStreetMap in 2004 as a free, editable map of the world. Millions of volunteers now map streets, paths and buildings; it is the base map in the mini-GIS below.
A GIS stacks layers. Choose a base map, then switch on water and the federal flood zones over Bradenton and the Manatee River. Which streets sit in the high-risk zone? What would a city planner, an insurer or a family buying a house want to know from this overlay?
Maps are pictures of places seen from above, like a bird would see them. Every good map has a title, a legend (what the symbols mean), a compass rose (north, south, east, west) and a scale (how far is far).
Try this: peel a clementine in one piece and try to lay the peel flat. It tears! That is why every flat map of our round earth is a little bit wrong. Then draw a map of your bedroom or your way to school with all four parts.
Three quick questions (3 questions · runs in your browser, nothing is sent)
Lessons:SS0 19 · Map Symbols and Legends (K–2)PreviewSS0 20 · Land and Water on a Globe (K–2)PreviewAM0 2 · Reading the Land on a Map (3–5)PreviewMA4 16 · A map with no legendPreviewE38 7 · Making the mapPreviewAPHG 26 · Capstone: A Field Study of a Real PlacePreview
Read: Mark Monmonier, How to Lie with Maps (3rd ed., 2018); Simon Garfield, On the Map (2012); Loreen Leedy, Mapping Penny's World (2000) for younger readers; Robert Louis Stevenson's Treasure Island (1883) began with a map he drew for his stepson; J. R. R. Tolkien drew the maps of Middle-earth before he finished the story.
Quiz: Maps that made the world (10 questions · runs in your browser, nothing is sent)
British Museum, Babylonian Map of the World (BM 92687): britishmuseum.org
Austrian National Library, Tabula Peutingeriana (Cod. 324); UNESCO Memory of the World (2007).
Library of Congress, Waldseemüller 1507 world map and its 2003 purchase: loc.gov
J. B. Harley and David Woodward, eds., The History of Cartography (University of Chicago Press), vols. 1–3, free online: press.uchicago.edu
John P. Snyder, Flattening the Earth (Chicago, 1993); USGS, Map Projections poster.
Royal Geographical Society and Survey of India records on the Great Trigonometrical Survey; Science Museum Group, the Great Theodolite.
UCLA Department of Epidemiology, John Snow site; LSE Library, Charles Booth's London; University of Richmond, Mapping Inequality.
U.S. Space Force / GPS.gov, GPS history and Selective Availability (May 2000): gps.gov
USGS, The National Map and historical topographic maps; FEMA, National Flood Hazard Layer; OpenStreetMap Foundation.
Federation of Tax Administrators, State Motor Fuel Tax Rates (2025).
newSchoolWorks.com · The Museum of Everyday Living · Bradenton, FL · SI paintings made for this explainer; historical maps and photographs from Wikimedia Commons under the licences shown on each card.