provides questionnaires and instructions, plus individual histories of each census. Pages 119-124 provide tables showing the "Population Items on Principal Census Questionnaires: 1790-2000."
"contains facsimile copies of the enumeration forms used in the decennial census of the United States from 1860 through 2000, and the American Community Survey (2000+)."
Map Guide to the U.S. Federal Censuses, 1790-1920 by William Thorndale & William Dollarhide
provides "a Longitudinal Tract Data Base (LTDB), which provides public-use tools to create estimates within 2010 tract boundaries for any tract-level data (from the census or other sources) that are available for prior years as early as 1970."