When California Was an Island: Peter Keating on the Cartography That Maps How We See the World

“Maps are communicating vast quantities of new knowledge that was only estimated. They convey this imaginative energy — an imaginative energy that maps today have lost, because today maps are so functional, so utilitarian.” — Peter Keating

In the sixteenth century, Spanish cartographers represented California as an island. They weren’t being careless. Nor were they drawing New Yorker covers. These 16th century cartographers were, instead, mapping the limits of both what they knew and what they imagined.

Cartography is as much an art as a science and maps always mirror how we see the world. Thus Peter Keating’s beautifully illustrated new book, Power Lines: Maps That Shaped the Way We See the World. Assembling nearly 100 of history’s most consequential political maps, Keating’s thesis is that maps are not neutral. They are arguments. Every map centers something — a religion, an empire, a people — and pushes something else to the margins. The story of cartography, then, is the story of power.

Five Takeaways

•       California Was an Island: The Power of Imagined Geography: In the sixteenth century, Spanish cartographers drew California as a large island off the coast of America. They weren’t being careless — they were mapping the edge of what was known and imaginable. Before any map can draw a border, Keating argues, it has to decide what is real. The T-and-O medieval maps placed Jerusalem at the center of the world, with the biblically admitted lands of Europe, Africa, and Asia radiating outward. Only slowly, and with great difficulty, did the Western cartographic tradition absorb the fact that there was a whole continent between their imagination and the Pacific.

•       The Oldest Tension in Cartography: Sacred vs Scientific: Keating identifies two traditions in constant tension throughout Western history. The cosmographical tradition: center what you know and believe, place your gods and sacred lands at the middle of the world, and mix fantasy with inquiry. The scientific tradition: starting with Ptolemy in ancient Greece and independently in ancient China, create maps that generals and kings could actually use to expand territory, find resources, and identify enemies. With Rome’s Christianisation, the cosmographical tradition dominated for nearly a thousand years. The Ptolemaic scientific tradition only re-emerged with the Renaissance and exploration.

•       Poland: The Most Erased Country in Cartographic History: Keating’s answer to his own question — which country has been wiped off maps most often yet survived? Poland. It disappeared from maps at least three times, divided and partitioned by more geographically fortunate powers — Habsburgs, Russians, Nazis — whose cultural and military might seemed overwhelming. And yet Poland survived every erasure in the hearts of its people. A 1956 map of Poland as a carnation, published by the communist government as a May Day celebration, reads — Keating argues — as subversive under the surface: a nation asserting its existence against the regime that claimed to represent it.

•       Lincoln’s Favorite Map: The Slave Density Survey: The most powerful map in the book: the 1861 Coast Survey, a non-ideological government project that shaded American counties by the density of enslaved populations. Lincoln studied it obsessively. He reasoned that where enslaved people were densest, Union troops could arrive as liberators and find support. Where they were rare — in predominantly white areas of the South — he could pursue accommodation and peace. The map shaped the Emancipation Pro