News & Politics

Where Do I Come From?

The April publication of the 1940 census records—the biggest pile of data ever released online—makes it easier to answer that.

Photograph courtesy of Flickr user Tommy and Georgie.

On the morning of April 2, National Archives employees and guests will gather at the Archives’ Federal Triangle headquarters and wait for an engineer in Silicon Valley to flip a switch. If all goes as planned, images of the 3.8 million handwritten forms from the 1940 census–which recorded the names and dozens of details about 132 million US residents as the country stood between the Great Depression and World War II–will go online at 9 am.

Preliminary population totals were released from August 1940 to April 1941 amid war bulletins from Europe and Asia. With the legally required 72 years now passed, the statistical minutiae collected by some 120,000 census takers going door to door becomes public record.

The 1940 census marks the first time a full census is going directly to digital–on a platform that the family-history site is hosting under a contract with the National Archives and Records Administration. Images of the pages were digitized at a National Archives center in College Park and will be posted at

The digital release is eagerly awaited by historians, social scientists, and others, but perhaps most by genealogy buffs. Internet technology has been a boon to family-history researchers. An endeavor once marked by hours of turning a crank on a microfilm machine now more often involves the high-speed retrieval of documents.

“As recently as ten years ago, only the truly dedicated were able to do genealogical research,” says Steve Morse, a computer-technology pioneer and enthusiastic family researcher who has shared information with the Archives regarding the census. “Now most of the research can be done right from your own home, in your pajamas, 24 hours a day.”

The 1940 data reflects the most domestically troubled decade of the 20th century. “It describes the country during the Depression,” says the Archives’ Connie Potter. “It reflects all of the economic dislocation.” Migration researchers will be aided by a 1940 question that asked where each household member lived in 1935. The 1940 census was also the first to ask about income. Josh Hanna, a senior adviser at, says 80 percent of Americans will either be in or have a relative in the 1940 data.

At least three major family-history websites will offer it for free, at least initially. But genealogy buffs should be forewarned: Because there’s no index of names, in the first weeks or months the census won’t be as easy to search as earlier censuses available online. Several groups, including and a consortium led by the Mormon site, will race to compile an index, but until one exists, researchers will need to know–or guess at–which census area, or Enumeration District, the relatives they’re hunting for lived in.

Researchers who know a city, a neighborhood, or, best of all, an address can use, a website developed by Morse and other volunteers, to determine which enumeration district to search for on the Archives site. Before the release of the 1930 census, Morse and volunteers developed a finding tool for major cities, and they expect to have more than 1,000 urban areas covered for the 1940 release.

The National Archives and are confident that user demand won’t crash the site, as happened in 2002 when the 1901 census of England and Wales was put online. Just a million users crashed the British site, but with today’s scalable cloud technology, says Rebecca Warlow, a digitization supervisor with the National Archives, as many as 10 million users a day can be accommodated on the 1940 site.

The release of that year’s data comes at an opportune time, as genealogy interest is growing rapidly in the US. The Archives’ first Genealogy Fair in 2005 drew 250 people; in 2010 it attracted 2,500, and last year’s drew 5,000. This year’s event takes place April 18 and 19 in outdoor tents on the Pennsylvania Avenue side of the Archives headquarters.

The decennial head count is required by the Constitution to set each state’s number of representatives in Congress. It’s also used to redistrict state and local government bodies.

Although the concept of a national census dates at least to pharaonic Egypt, some nations have given up person-by-person counts and instead use statistical estimates. France’s last full enumeration was in 1999.

Wonder what your neighbor said in the 2010 census? Mark your calendar for April 1, 2082, when all of those files will be released.

This article appears in the April 2012 issue of The Washingtonian.