Heard the latest news? It's from 1940.

At 8 a.m. Monday, the federal government will release reams of information from that year's census, snapshots of 132.2 million Americans, more than 20 million of them still alive. For the first time, this info will be available online for free (at 1940census.archives .gov), including 3.8 million images of the handwritten forms.

To learn more about Grandpa Ulf or Aunt Gertie, you'll need more than their names, said Tracey Baker, head of reference at the Minnesota Historical Society. More important is an address, which is not as easy as it sounds. "Some streets may have changed names or no longer exist," said Baker, who recommends Stevemorse.org/census to help users locate urban EDs (enumeration districts, often a ward or precinct).

Finding people who resided "out in the country" is much easier. "If your family lived on a farm in Eagan," Baker said, "you might find them in the Eagan township" (ED 19-4) at the National Archives site.

Clearly much has changed in the 72 years since that census, which has been sealed by law until now. Back then, 5 percent of Americans had bachelor's degrees (compared with 28 percent in 2010), California had the fifth-largest population with 6.9 million (37.2 million), and 28.9 percent of women ages 20 to 34 had never married (55.6 percent now).

In 1940 the nation was recovering from the Great Depression, and "a lot of the census questions have to do with employment and economic conditions," Baker said,

Baker will be among the history buffs digging into the data. Her focus: "I like looking at ... those lost neighborhoods like Bohemian Flats and Swede Hollow, who's living there and how they fared."