About the 1940 Census
The first Federal Population Census was taken in 1790, and has been taken every ten years since. However, data from recent censuses are not available because of a 72-year restriction on access to the Census. Most researchers find it helpful to begin with most recent Census that has been released and work backwards to locate people in earlier generations.
Most of the 1890 Census was destroyed in a Department of Commerce fire, though partial records are available for some states.
Census information is available here
Access the 1940 Census
However, there is currently no index for the census. The key to finding your ancestor is knowing the enumeration district (ED). For help finding the enumeration district --- Click here.
Earlier census records are available at the library through subscription databases (Ancestry and Heritage Quest), microfilm and in books.