A nationwide population census is mandated by Article 1, Section 2 of the United States Constitution. The first census began on the first Monday in August 1790. Six basic questions were asked of the populace in the original 13 states, plus the districts of Kentucky, Maine, and Vermont, and the Southwest Territory (Tennessee). There is no evidence of a 1790 census in the Northwest Territory.
The most recent decennial census was taken on April 1, 2000, and consisted of a short form with 8 questions and a long form with the same 8 questions plus 38 additional questions. The geographical coverage included 50 states, the District of Columbia, American Samoa, Guam, U.S. Virgin Islands, The Commonwealth of the Northern Mariana Islands, and Puerto Rico.
The San Francisco Public Library has all the decennial census volumes: 1790 - 1990 and computer access to 2000. The Census 2000 is the first census for which the Internet site is the primary means of disseminating the data. The data is released first on the Census Bureau's American FactFinder Web site. In addition to formatted tables, the Census Bureau Web site has maps and data sets available for downloading, printing, viewing and manipulating.
The Census Bureau has started to load historical census data on the Internet. The coverage is selective and covers censuses from 1790 to 1990.
The Census Bureau's Web page provides Web access to census data plus all of the Bureau's statistical series, publications, products, and programs. Using the Subjects A to Z is an efficient way to research all kinds of census-related topics.