What population did the first U.S. census record in 1790?

The first U.S. census recorded a population of 3,929,214 in 1790.

The census counted inhabitants as of August 2, 1790, under authority granted by Article I, Section 2, of the Constitution. United States marshals, rather than a specialized census agency, visited households and compiled the returns.

The count covered the thirteen states and the Southwest Territory. Virginia was the most populous state, with 747,610 people, while Delaware was the least populous, with 59,094. Vermont was not included in the original enumeration because it joined the Union in 1791.

The total included free people and enslaved people under categories specified by the law of the period. George Washington and Thomas Jefferson both suspected that the census undercounted the population because of difficult travel, scattered settlements, and incomplete participation. The results were published in 1791.