Census Information: Decennial Census - U.S.

The United States Constitution includes directives for carrying out a census of the population every 10 years.

About The Early Census

For detailed information on the evolution of the census see Measuring America: Decennial Censuses from 1790 to 2000 or access a detailed spreadsheet documenting Population and Housing Items on the General Census Schedules 1790-2000 from the University of Michigan Library.

1790 - 1900 Decennial

The decennial census has been taken since 1790. From 1790-1900, the Census Office was part of the Department of the Interior, and the Censuses were classed under "I." Starting with the 13th Decennial Census (1910), the Census Office (under the name Bureau of the Census) was moved to the Dept. of Commerce and classified under "C."

We also have the Censuses from 1790-1900 on microfilm in the main microfilm collection at: HA214 .A12. This set includes the main volumes that we own and also other reports and publications that we may or may not own. For information on what is on the reels, use the index at: Z7554 .U5 R47 1975.

1910 - 1950 Decennial

The 13th Decennial Census was the first census classified under the Department of Commerce. Earlier censuses were classified under the Department of the Interior. The 17th census (1950) was the last decennial census to have topics classed together. Starting with 1960, each topic has its own classification.

Finding US Documents: SuDoc Call Numbers

Government Documents are assigned call numbers based on the agency or department printing the information, called the SuDoc Classification (Superindent of Documents). It is a bit different from the regular Library of Congress or Dewey systems. Find the collection on the 4th Floor of the library. Can't find what you need? For assistance, ask at the Reference Desk on the 2nd floor or Ask Us Online

Core Resources

Portland State Library has both print and online access to historical decennial census data and tables.

Online access tools include:

Find in the Library

Search the PSU Library catalog to find Census holdings in print or microform. Suggested terms include:

  • decennial
  • census
  • population
  • housing

Census publications are located on the 4th floor of the Library.

Search the Catalog


Results include both print and ebooks, available from Portland State Library and the Summit Libraries.