The first United States census in 1790 counted 3,929,214 people.
The census was conducted under the constitutional requirement that population be counted every ten years. The first enumeration covered the eleven states that had ratified the Constitution by the time of the count, along with the southwest territories then included in the federal enumeration system.
U.S. marshals and their assistants collected the information by visiting households. The census recorded free people, enslaved people, and other categories separately rather than producing a modern race-neutral population count. Enslaved people were counted under the Constitution’s three-fifths rule for apportionment, which affected representation and taxation but did not mean that individuals were valued as three-fifths of a person.
The result was used to apportion seats in the House of Representatives. Virginia had the largest population, while Delaware had the smallest among the states counted. Later research found that the original total may have undercounted some residents.