The National Historical Geographic Information System (NHGIS) provides, free of charge, aggregate census data and GIS-compatible boundary files for the United States between 1790 and 2010. A project of the Minnesota Population Center.
The Statistical Abstract of the United States, published since 1878, is the authoritative and comprehensive summary of statistics on the social, political, and economic organization of the United States.
City of Portland site for metropolitan area geographic data. Search by street address or geography for many types of data including assessed and market values, as well as elevation, crime data, and school district information. More info...
Advances the economic, environmental, and social goals of the Portland metropolitan region by gathering and disseminating credible information, convening regional partners, and stimulating dialogue and action about critical regional issues.
Includes Surveys such as the 1990 and 2000 Decennial Census of Housing and Population; 1997 and 2000 Economic Census; and annual American Community surveys. Portal updated in 2011.
For more information see the guide for Using American FactFinder from St. Mary's University.