No April Fools: Individual-level data from the 1950 Census was released today (April 1, 2022) to the rejoice of historians, archivists and others who long-awaited the new release.

The data can be searched here. reports:

Sequestered by law for 72 years, the personally identifiable and detailed data from the mid-century census will be posted on a new website recreated by the National Archives and Records Administration. The digitized records from population schedules to enumeration district maps will be free to access.

The 1950 data provides an insight into a population on the brink of transformation, said Marc Perry, a senior demographer for the U.S. Census Bureau who called the data set a “genealogy gold mine.”

For privacy reasons, access to “personally identifiable information contained in decennial census records is restricted to all but the individual named on the record or their legal heir for 72 years,” according to the National Archives. The 2020 (2021) census data won’t be released until 2092.

So, why 72 years? According to the  Pew Research Center, the most common explanation is that 72 years was the average lifespan at the time the law was established.

Because of the restriction on access to the records, 1940 is the most recent census year currently available.