The 1790 United States census recorded a total population of 3,929,214 people.
Conducted under the direction of Secretary of State Thomas Jefferson, the census was the first population count required by the new Constitution. Marshals collected information from the states and territories, generally by visiting households and recording names of heads of families and population categories.
The published total included 3,172,006 free people and 757,208 enslaved people. The count covered the original thirteen states, plus the districts of Kentucky, Maine, and Vermont, although Vermont joined the Union as a state in 1791.
The census was used to apportion seats in the House of Representatives. Pennsylvania had the largest population, followed by Virginia, while Delaware had the smallest among the original states. Historians note that the enumeration likely missed some people, particularly enslaved people and residents in remote areas.