Series: M432   Rolls: 1 - 1009 1850 Facts 1. Seventh U.S. decennial population census. 2. U.S. population: 23.2 million     (20.0 million free, 3.2 million slave) 3. Census conducted by U.S. marshals under the     direction of the Census Office appointed by the     U.S. Secretary of the Interior. 4. Census day: 1 June 1850. 5. Mandated copies: Three sets, one to the county court,     a second to the secretary of the state (or the territory)     and the last to the U.S. Secretary of the Interior.