It was a decade when tens of millions of people in the U.S. experienced mass unemployment and social upheaval as the nation clawed its way out of the Great Depression and rumblings of global war were heard from abroad.

Now, intimate details of 132 million people who lived through the 1930s will be disclosed as the U.S. government releases the 1940 census records online for the first time on April 2.

The records will be free and open to anyone on the Internet, but they won't immediately be name searchable.

For genealogists and family historians, the 1940 census release is the most important disclosure of ancestral secrets in a decade.

Scholars expect the records to help draw a more detailed portrait of a transformative decade in American life.

Copyright 2013 by The Associated Press. All Rights Reserved.