Below are some commonly requested statistics, both online and in print. For a VERY comprehensive list including U.S. and international statistics sources, as well as topical sources, see Statistical Information World-wide.
Search all U.S. Census data through this new (July 1, 2019) portal. Supercedes American Fact Finder.
Provides aggregate census data and GIS-compatible boundary files for the United States,1790 -- 2000.
Digest of major statistics from many U.S. agencies including the Census Bureau since 1878.
From: Library and Archives Canada website