The first United States census counted the nation’s population in 1790.
The census recorded the population as of August 2, 1790, following a requirement in Article I, Section 2 of the Constitution. Its published total was about 3.9 million inhabitants, including free people and enslaved people counted under the categories specified by federal law.
Congress assigned the work to U.S. marshals rather than creating a permanent census agency. Marshals visited households, posted completed schedules publicly, and transmitted the totals to the president. Thomas Jefferson, then secretary of state, oversaw the census administration.
The census covered the thirteen states and the Southwest Territory, but Vermont’s enumeration was taken later, after it joined the Union in 1791. Historical totals have been revised because some original returns were corrected, and records from several states were later lost. The census established the decennial population-counting system still used today.