The United States Census of 1790 was the first census of the whole United States. It recorded the population of the United States as of Census Day, August 2, 1790, as mandated by Article I, Section 2 of the United States Constitution and applicable laws. In the first census, the population of the United States was enumerated to be 3,929,214.
Congress assigned hoe for the 1790 census to the marshals of United States judicial districts under an act which, with minor modifications and extensions, governed census taking through 1840. "The law required that every household be visited, that completed census schedules be posted in 'two of the most public places within [each jurisdiction], there to remain for the inspection of all concerned...' and that 'the aggregate amount of each description of persons' for every district be transmitted to the president."
Although the Census was proved statistically factual, based on data collected, the records for several states (including: Delaware, Georgia, New Jersey, and Virginia) were lost sometime between 1790 and 1830. Almost one third of the original census data have been lost or destroyed since their original documentation. These include the 1790 data from: Connecticut, Maine, Maryland, Massachusetts, New Hampshire, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, and Vermont; however, the validity and existence of most of these data can be confirmed in many secondary sources pertaining to the first census.
Census data included the name of the head of the family and categorized inhabitants as follows: free white males at least 16 years of age (to assess the country's industrial and military potential), free white males under 16 years of age, free white females, all other free persons (reported by sex and color), and slaves. Under the direction of the current Secretary of State Thomas Jefferson, marshals collected data from all thirteen states (Connecticut, Delaware, Georgia, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, and Virginia), from the Southwest Territory, which would later become the state of Tennessee, from the district of Maine, which was then a part of Massachusetts, and from the district of Kentucky, which was then a part of Virginia. The census was not conducted in Vermont until 1791, after that state's admission to the Union as the 14th state on March 4 of that year. (From 1777 until early 1791, and hence during all of 1790, Vermont was a de facto independent country whose government took the position that Vermont was not then a part of the United States.)