Historical U.S. census and vital records

39.8 million persons

Geography: Add Kansas, Nevada, Nebraska

Publications: https://www.census.gov/prod/www/decennial.html

• Census reports compiled from the original returns of the ninth census (June 1, 1870,) under the direction of the secretary of the interior, by Francis A. Walker, superintendent of census. Washington, D.C.: Government Printing Office, 1872. Data and Statistical Services (DSS): Decennial Census, Oversize HA201.1870 .A2q
• A compendium of the ninth census (June 1, 1870). Washington, D.C.: Government Printing Office, 1872 .
• Statistical atlas of the United States based on the results of the ninth census 1870: with contributions from many eminent men of science and several departments of the government. New York: Julius Bien, lith., 1874.

50.1 million persons

Geography: Add Colorado, Alaska as a territory.

Publications:  https://www.census.gov/prod/www/decennial.html

62.9 million persons

Geography: Add Idaho, Montana, Wyoming, North Dakota, South Dakota. First coverage of Indian Territory.

Publications: https://www.census.gov/prod/www/decennial.html

Note: The original documents of the 1890 census were destroyed in a fire in 1921, and only fragmentary material remains.

75.9 million persons

Geography: Add Utah, Hawaii as a territory. First count of U.S. citizens living abroad.

Publications:  https://www.census.gov/prod/www/decennial.html