National Historical Geographic Information System

John S. Adams, University of Minnesota
Catherine A. Fitch, University of Minnesota
Steven Ruggles, University of Minnesota

The Minnesota Population Center has undertaken a major project with exciting implications for spatial population analysis. The National Historical Geographic Information System is creating a database incorporating all available aggregate census information for the U.S. between 1790 and 2000. This project includes all surviving machine-readable aggregate census data for the U.S. and will add new data transcribed from printed and manuscript sources. These data will be freely disseminated on the web in a Geographic Information Systems framework. We are creating new census tract maps back to 1910, state and county maps to 1790, and additional maps where feasible. Availability of high-quality boundaries for key statistical areas will allow us to reconcile changes in census geography. Census data, XML encoded metadata, and boundary files will be disseminated through an integrated web-based data access and mapping system. For additional information on the project, see http://www.nhgis.org/