The first U.S. census, completed in 1790, reported a population of 3,929,214.
The census was authorized by the Constitution and conducted under Secretary of State Thomas Jefferson. Marshals gathered information from households across the fifteen states that existed at the time, along with the Southwest Territory.
The enumeration counted free people and enslaved people separately and classified some free people by age and sex. It did not use the detailed personal questions common in modern censuses, but it established the federal government’s regular population-counting system.
The published total is sometimes remembered as approximately 3.9 million. The exact reported figure is 3,929,214, although later historical adjustments and discussions can produce different numbers for particular jurisdictions or categories.