Statistical Abstract of the United States statistics collected by the federal government and public and private organizations on social and economic conditions in the United States. Supplies tables of demographic data, industry statistics (divided into sections including agriculture, finance, technology, transportation, and services), labor statistics, and a summary of the latest economic census.
United States Census Bureau The ultimate place to find comprehensive and detailed demographic information on the United States. Now includes Census 2000 data. Pay attention to the browsable index "Subjects A to Z" and the categories on the home page. "American FactFinder" offers detailed demographic information on state, county, and city levels.