National Archives Releases 'Secret' 1940 Census Data

The Contra Costa Times reported that records that were kept secret for more than seven decades about the 1940 U.S. census were finally released today at the National Archives, which is based in San Bruno.

According to the Contra Costa Times, the data was kept confidential for 72 years to protect privacy. But the release of the information, online and at the San Bruno branch, should now shed a new light on that period of the country's history.

The raw data from the 1940 census records every home in the country: who lived there, what they did for a living and how much money they made, where they came from, their education, the wars they fought in. Statistical information from the 1940 tally was used to determine congressional seats in the 1940s, calculate population trends and gauge the effectiveness of New Deal economic programs. 

More than one million people who fled West in the 1930s to escape rural poverty and the Dust Bowl were first counted in California in 1940.

"It really tracks what happened after the Great Depression," said Marcy Goldstein, director of the Bay Area branch of the National Archives. "It was a time of a lot of movement."

Just like with many parts of the West, 1940 was a crucial year for San Bruno, according to Darold Fredricks' San Bruno history book as part of the Images of America series.

When World War II began, the Tanforan Race Track was turned into Navy facilities, the airport became an Army airbase and EiMac, the city's only large business at the time—which manufactured vacuum tubes for communication equipment—became a key wartime supplier.

The city also grew in population. In 1940, according to Fredricks, San Bruno only had a population of 4,000 people. By the mid-1940s, the population jumped to 15,000.

To learn more about the new release of records made public by the National Archives, visit www.archives.gov/research/census/1940/. The San Bruno branch of the National Archives is located at 1000 Commodore Drive and is open from 7:30 a.m. to 4 p.m. every weekday except for Wednesday. On Wednesday, it is open until 5:30 p.m.

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