The  complete 1940 Census dataset was released recently by the National Archives and Records Administration (NARA). This is the first time a complete census dataset has been made available in full to the public.

What’s in the 1940 Census Dataset?

According to NARA, the 1940 Census dataset contains

…over 15 terabytes of data–includes the metadata index, the population schedules, the enumeration district maps, and the enumeration district descriptions for the 1940 Census records. Until now, this data was available through the Catalog and the 1940 census websites, but not in bulk. This release aligns with the National Archives’ effort to Make Access Happen for the records in its care.

Big Data Projects Coming

The primary value of this dataset lies mostly with institutions. They’ll harness their computing power to combine the 1940 census dataset with maps and infographics. The metadata index for the 1940 Census dataset alone is 251 megabytes, and all of the 3.7 million images from the population schedules, the enumeration district maps, and the enumeration district descriptions total over 15 terabytes. This dataset reflects the 1940 Census records that are also available on NARA’s 1940 Census website and in the National Archives Catalog. The resulting Big Data projects will help genealogists in the future. I can’t wait to see what insights are gained.

1940 Census Dataset for Genealogy

Need help with the 1940 census right now? Releasing this dataset makes it easier to find census maps and enumeration districts at NARA. Browsing through specific enumeration districts at NARA’s website is also improved. So if you’re still looking for an elusive relative in 1940, try this:

  • Find census maps and descriptions to locate an enumeration district.
    To find a person in the census, you first need to determine the appropriate enumeration district number. This can be found by searching census district maps and descriptions.
  • Browse census images to locate a person in the 1940 census.
    Census images are organized by enumeration district number. Once you’ve located the correct one, you can begin to browse census images to look for your ancestor.
  • Save, share, and download images to save your work and share with family members.
    When you locate a census image, you can easily save, share, or download the image for future reference.

Examples of Images from the 1940 Census Data

See one of many 1940 Census Enumeration District Descriptions in the featured image above. This image describes four districts for Alaska Territory, First Judicial Division County. And the two images below show the census return for the same area for ED 1-1, followed by the map for ED 1-2 through 1-4.

1940 Census Dataset Released
Above: 1940 Census population schedule for Alaska’s First Judicial Division,
Enumeration district 1-1. National Archives Identifier 1240633441940 Census Dataset Released1940 Census enumeration district map for Alaska’s First Judicial Division,
Enumeration districts 1-2 through 1-4. 
National Archives Identifier 5822485
Having the 1940 census dataset released is a big advance on the part of NARA. I can’t wait to see the future projects from this release that will help our family history research.