How did the 1870 United States census change the counting of Black Americans?

The 1870 United States census was the first decennial count conducted following the ratification of the Fourteenth Amendment in 1868.

Prior to this amendment, the U.S. Constitution’s "three-fifths compromise" had counted enslaved individuals as only three-fifths of a person for the purposes of apportionment. The 1870 census reflected the fundamental legal shift established by Section 2 of the Fourteenth Amendment, which mandated that representatives be apportioned based on the "whole number of persons in each State," thereby officially counting formerly enslaved Black Americans as full persons for the first time in the nation's history. This change was a direct consequence of the abolition of slavery via the Thirteenth Amendment and the subsequent granting of citizenship rights to formerly enslaved people.12