United States Enumeration District Maps for the Twelfth through the Sixteenth US Censuses, 1900-1940
Digital images of National Archives microfilm publication A3378, reproductions of enumeration district maps for the 1900, 1910, 1920, 1930 and 1940 censuses. Each census year, the nation was divided into enumeration districts. An enumeration district was an area that could be covered by a single census taker in one census period. Enumeration districts varied in size from one city block in urban areas to an entire county in rural areas.