The U.S. Constitution mandates that "an actual enumeration" be conducted every 10 years. The first census separates people into the head of household, free white males over 16, free white males under 16, free white females, all other free people by "sex and color, and slaves." Unfree white people, still in existence in 1790, were not counted. At this point "free" and "white" are not seen as the same thing, though this will have changed by the next census. Enslaved Black people are counted as 3/5ths of a person for the purposes of taxation and representation.