The first United States census recorded a population of 3,929,214 in 1790.
The census counted residents as of August 2, 1790, under authority granted by Article I, Section 2, of the Constitution. It was the first nationwide population enumeration conducted by the new federal government and provided the basis for apportioning seats in the House of Representatives.
Congress assigned the work to U.S. marshals and their assistants. Enumerators visited households and recorded categories such as free people, enslaved people, and other residents. The census covered the original states plus the districts of Kentucky, Maine, and Vermont, as well as the Southwest Territory.
Virginia was the most populous state in the enumeration, with 747,610 people, while Delaware was the least populous, with 59,094. The total is sometimes presented differently in later summaries because the 1790 count excluded some Native Americans living outside the taxed population and used categories unlike modern censuses.