Several news organizations are broadcasting today that "On Aug. 1, 1790, the first United States census was completed, showing a population of nearly 4 million people."
Well, not quite.
The enumeration was to begin on the first Monday of August, 1790—i.e. the second day of August. According to Ancestry.com, "The marshals were expected to finish the census within nine months of the Census Day—by 1 May 1791. Although most of the returns were in long before the deadline, Congress had to extend the count until 1 March 1792. By that time some people probably were counted who had not been born or present in 1790."