Cartograms and Demography Go Together Nicely

A cartogram is a map in which each area is sized proportionately according to some particular characteristic. Slate has a blog called "The Vault" by Rebecca Onion, which focuses on historical things, and today she highlighted some cartograms ("distorted" maps as they were called) related to population topics in 1930.

The first map (seen here in zoomable format) sizes states according to total population and colors cities with more than 50,000 residents a bright kelly green. The second sizes states in proportion to the number of residents who reported living in an urban area.

The maps show how Americans clustered in the north and the east, even after the storied westward expansion of the 19th century. New York and New Jersey bulge into the ocean, while Illinois, Wisconsin, and Michigan take up their share of real estate. Depicted before its wartime and postwar population boom, California appears surprisingly small, and the Mountain West and the Sun Belt barely register.

Ah, how times change! 

Of course, if you've looked at the cover of my book, you know that I like cartograms. Ever since the first edition came out 35 years ago, the cover has been a cartogram in which each country of the world is sized according to its total population, with each square on the map equal originally to one million people, but now 2 million because the population of the world has increased by 60 percent since the first edition came out (no causal connection!). Although there are now computer programs that can create cartograms, I  have always done it by hand on graph paper in order to get exactly the shapes that I want (well, full disclosure, I now pay a graduate student to do it under my supervision).