The Constitution requires that a census of the United States shall be taken every ten years. The first census was taken in 1790 under the super-vision of the President; subsequent censuses, to and including that of 1840, were taken under the supervision of the Secretary of State. In 1849 the supervision of the census was transferred to the newly organized Department of the Interior, and continued under the control of that department until the passage of the act of 1903, creating the Department of Commerce and Labor; by this act the Census Bureau was transferred to the new department. Congress, by act approved March 6, 1902, made the Census Bureau a permanent bureau of the Government.
The work of the Census Bureau is divided into two main branches, namely, the decennial census and special statistical inquiries, the latter mostly made in the intervals between the decennial censuses. The Fourteenth Decennial Census was taken as of January 1, 1920. It covered: (1) population, (2) agriculture, (3) manufactures, (4) forestry, and (5) mines, quarries, oil and gas wells.