The first U.S. census counted 3,929,214 people in 1790, creating the earliest official population baseline for the nation approaching its 250th anniversary.
Congress authorized the census under Article One of the Constitution, which required a population count for apportioning seats in the House of Representatives. Marshals collected information from August 1790 into 1791, and Secretary of State Thomas Jefferson received the compiled results.
The count covered the thirteen states, the districts of Kentucky and Maine, and the Southwest Territory. It did not include Native Americans who were not taxed, and it counted enslaved people under the constitutional three-fifths rule for representation rather than treating that figure as a complete measure of the population’s social reality.
The 1790 total is often remembered incorrectly because it is close to several rounded estimates. The official published total was 3,929,214. The census established the decennial counting tradition that continues in the United States today.