The 1790 U.S. census recorded a total United States population of 3,929,214. This first federal census counted people in the states and the southwest territory, establishing a population baseline for the new republic.
The census was conducted under the direction of Secretary of State Thomas Jefferson after Congress passed the Census Act of 1790. Marshals collected information mainly by visiting households, rather than using modern self-response forms. The enumeration included free people, enslaved people, and other categories defined by the law.
The result mattered politically because population totals determined representation in the House of Representatives. It also exposed how unevenly populated the country was: Virginia was the largest state, while Delaware was among the smallest. The total did not include Native Americans living outside the taxed or settled population covered by the census rules, making comparisons with modern population counts imperfect.
Later censuses used increasingly detailed questions and more systematic methods. The 1790 count therefore serves both as an important historical number and as the starting point of the United States’ continuing decennial census tradition.