Geography: Add Arizona, New Mexico, Oklahoma; Puerto Rico (first census 1899; then 1910 and decennially.)
Available for these geographic areas:
Boundaries of geographic areas may be determined using a combination of Census Descriptions of Geographic Subdivisions and Enumeration Districts, (a microfilm set kept in the Newspaper Room at the State Library, call number F93 .U5 1978, reel 28) and town maps. (Note that not all data is available for all geographic areas)
From the U.S. Census Bureau site (posted on several pages for historic censuses):
"A Note on Language
Census statistics date back to 1790 and reflect the growth and change of the United States. Past census reports contain some terms that today’s readers may consider obsolete and inappropriate. As part of our goal to be open and transparent with the public, we are improving access to all Census Bureau original publications and statistics, which serve as a guide to the nation's history."