On April 2, 2012, the National Archives and Records Administration (NARA) released the 1940 U.S. Census online. This marked the first time the agency has released an official decennial census online. The free official website is available at: http://1940census.archives.gov/
This is the 16th decennial census, marking the 150th anniversary of the census. The 3.9 million images constitute the largest collection of digital information ever released by the National Archives. The website, hosted by Archives.com, includes a database of Americans living within the existing 48 states and 6 territories on April 2, 1940.
The census database is now only searchable at the enumeration district level. An enumeration district is an area that a census taker could cover in two weeks in an urban area and one month in a rural area.
However, within six to nine months, a host of volunteers will have completed a name index, allowing researchers to completely bypass the enumeration districts. FamilySearch.org is coordinating the volunteer effort, and claims that over 100,000 volunteers have already stepped forward for this massive undertaking, including the members of 612 genealogical societies. The coordinators of this effort hope to ultimately “crowdsource” the work to 300,000 volunteers. Volunteers can sign up and receive documents online.
A National Archives video short on YouTube http://tiny.cc/1940Census and on provides a “behind-the-scenes” view of staff preparations and gives viewers tips on how to access the data once it is launched on April 2. This video is in the public domain and not subject to any copyright restrictions. The National Archives encourages the free distribution of it.