At 9 AM on 2 April 2012, the National Archives and Records Administration made history by releasing the 1940 Federal Census online for free.
This will be the first time the United States Government has ever released Census records to the general public for free in a digital format. Previously, all United States Census records were released on microfilm and digitized by private companies.
Fast Facts about the United States Census
- The United States has conducted a census every ten years since 1790.
- The Census is used to allocate the number of seats each state gets in the House of Representatives.
- Before 1950, every political district used “enumerators” who were citizen canvassers who went door to door with Census forms and orally conducted the survey of each home. The 1940 Census was the last to be conducted this way. In 1950, the United States switched over to forms mailed directly to individual residences.
- Native Americans were excluded from Census reports throughout the nineteenth century and only 3/5s of enslaved African Americans held in bondage before Reconstruction were counted. This was due to Article 1, Section 2, Paragraph 3 of the United States Constitution which allowed white slaveholding men in the United States South to get an additional 3/5s weight added to their vote in order to ‘represent’ their slave population.
- The 1940 Census could not legally be released until 2 April 2012 because of a statutory 72-year restriction (92 Stat. 915; Public Law 95-416; October 5, 1978). The one loop-hole to the 72-year ban is that an individual can write to the Bureau of the Census Age Search Service to gain information about themselves documented in any census report or information on anyone deceased.
How is the 1940 Census unique?
- Although Franklin D. Roosevelt was the only United States President elected beyond two terms (he served between 1933 and 1945), this was the only census taken during his tenure.
- This census will provide invaluable information about daily American life during the Great Depression (1929-early 1940s). Historians will be able to track migration patterns of individuals, families, and even entire communities who fled the Dust Bowl for California.
- The 1940 census contained new supplementary questions which give intimate insight into major shifts in immigration, changing gender roles and consumption patterns. Additional questions asked the place of origin for both their mother and father. This information is crucial for historians and genealogists tracking the lineage of an individual. The Census also asked which language was spoken in their childhood home. For historians interested in gender, the 1940 Census provides crucial demographic information about how many live births a woman had had by 1940, whether they had ever been previously married, and age at their first marriage. For the first time, the 1940 Census also asked whether a family owned their home or rented.


The world-renowned researchers at the National Archives have compiled a useful webpage to help you use the 1940 Census. They have also created these videos below which provide both a historical overview of the Census and how to begin using it for research and in the classroom.
Once you locate the individuals you would like to research in the 1940 Census, work backwards in time. Here is a useful video with additional tips and suggestions.