What was the name of the first U.S. census, conducted in 1790?

The first U.S. census was the 1790 United States census.

The census began on August 2, 1790, under the authority of the Constitution, which requires a population count for congressional representation. Marshals and their assistants collected information from households in the 13 states, five other jurisdictions, and parts of the western territory.

The official count recorded 3,929,214 people, including enslaved people and free people of color. It excluded most Native Americans because the constitutional system did not count tribal members living outside the taxed population. The census asked for limited information compared with modern population surveys, including household heads and broad categories of other residents.

George Washington and Thomas Jefferson were among the national leaders who reviewed the results. The count helped determine the initial apportionment of seats in the House of Representatives. Later censuses became increasingly detailed, but the 1790 enumeration established the recurring federal population-counting tradition.