April 9, 2012

The ‘72-Year Rule’ Governs Release of Census Records

72

The National Archives released individual-level records from the 1940 Census for the first time on April 2. The waiting period is mandated by a federal law that protects the data for 72 years after the head count is completed.

Individual-level records from the 1940 Census have been released by the National Archives for the first time, unlocking a digital treasure chest for people researching their family histories. When records were made available on April 2, demand was so great that the website was paralyzed.

The records were released under a federal law that protects individual-level records for 72 years after the census is taken. The law, passed in 1978, was an outgrowth of an agreement between the Census Bureau and National Archives. 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.

Why 72? The most common explanation is that 72 years was the average lifespan at the time, although documentation corroborating this is sparse.

The 1940 Census counted 132.2 million Americans, 89.8% of whom were white. At the time there was no census category for Hispanics (it was not added to census forms until 1980). The count found that a quarter of adults ages 25 and older had at least a high school diploma, compared with 86% today. Only 44% of households owned their own homes, compared with 65% in 2010.

For the first time, the 1940 Census used random sampling to survey the population in an effort to gain representative information about conditions during the Great Depression which was a way of gathering more information without burdening all respondents. Read More