The first U.S. census recorded a national population of 3,929,214 in 1790.
The census was conducted under the direction of Secretary of State Thomas Jefferson. Marshals collected population information in the fifteen states then belonging to the Union, along with the Southwest Territory, which later became Tennessee.
The count included free people, enslaved people, and other categories defined by the law of the time. It did not provide a modern, comprehensive demographic picture, and the census methods reflected the exclusions and racial classifications of the early republic.
The reported total is sometimes confused with estimates for the thirteen colonies before independence or with later census totals. The 1790 census established the decennial census tradition that remains central to congressional apportionment and national statistics.