The Census (or Enumeration) is required by Article 1 Section 2 of the United States Constitution. Every ten years we count. From 1790 to 1840 only the name of the head of house was recorded. 1850, 1860 and 1870 lists the name of each member of the household. 1880 and after lists the relationship to the head of house. 1900 lists month and year of birth. 1900 through 1930 list year of immigration and naturalization. 1940 lists citizenship if foreign born. 1950 will be available in 2022.
Footnote: Census takers were people just like us. I have seen interesting mistakes on the census. Did the census takes write it down wrong or did his informant misinform him? I know a family that was counted from both sides of the state border and others I just can not find. I have also found valuable clues I would not otherwise know.