On what date did the first United States census count the national population?

The first United States census counted the national population as of August 2, 1790. The census followed the Constitution’s requirement that population be counted for congressional apportionment and direct taxation.

Congress assigned the work to marshals of the federal judicial districts. Instead of relying only on written forms, marshals or their assistants visited households and compiled returns under categories established by law. The original enumeration recorded roughly 3.9 million inhabitants, including free people and enslaved people.

Virginia was the most populous state in the first census, while Delaware was among the smallest. The census counted people using categories that reflected the legal and racial system of the period, including slavery and restrictions on how certain residents were classified.

The first census created a baseline for representation in the House of Representatives. Decennial censuses have continued ever since, though the questions, methods, and population categories have changed substantially.