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Many people concerned about their privacy with public records today have no idea just how much a historian can uncover about people walking the planet not that long ago. The federal census is one tool we house historians use to reveal interesting tidbits about those owners, and even the renters or lodgers in your house long ago. The last available in detail for researchers in the 1930 census. (The 1940 census won't be released in detail until 2012, 72 years or an average life span after it was recorded)
The 1930 census includes the more detailed information than any other prior census. It was taken live by enumerators traveling door to door, as seen at left. It listed all the people in the household at that time; the head of household was listed first, followed by everyone in the house as they related to him or her: wife, husband, children, son-in-laws, etc. It listed everyone's age, where they were born, and even where both of their parents were born. If they were foreign born, it indicates when they arrived in the US, became a citizen, or were naturalized.
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Another interesting aspect of the 1930 census was the fact that unlike prior census, it recorded what the home owner thought their house was worth (a year after the stock market crash), or what they were paying in rent. Washington, DC homeowners might be shocked how little their house was worth that year, or that you could rent a nice townhouse in DC for about $35 a month that year.
Census enumerators also recorded race, although they frequently made errors because it was a guess by observation, rather than a question of the subject. Census enumerators that year were instructed: “to be particularly careful in reporting the class mulatto. The word is generic, and includes quadroons, octoroons, and all persons having any perceptible trace of African blood.” Importantly, it was up the census taker to observe and determine race, not the subject being interviewed, often resulting in a multitude of errors. Anyone of the Asian race were classified as white, while those born in India might have been classified as mulatto.