(1940 - 2000)
Welcome to MapUSA
Designed by Brown University sociologist John Logan, Map USA provides maps and census data at the tract and county level from 1940 to 2000. Scholars and the public can gauge population trends that affect neighborhoods, cities and regions around the country.

  • Click HERE to open the system.
  • The map will open showing the continental United States.
  • At this point the zoom tool is on. Use the cursor to draw a rectangle around the part of the country that you want to map.
  • Select a decade to display on the upper right. By default you will start with 1940.
  • Choose a feature category and a specific variable to map. You can select either a county variable such as 40 (CNTY) % black race or a tract variable such as 40 (TRCT) % black race.
  • Along the left-hand side you will find tools to zoom in or out, to pan, to print, to “identify” (click on this tool then on a location on the map to see the exact data for that area), to search for locations that match specific attributes, and to draw a polygon to select a set of tracts or counties to “identify.”