Prior to which amendment where salves counted as only three fifths of a person?

Prior to the 14th Amendment, slaves were counted as three-fifths of a person for the purposes of congressional representation and taxation, as established by the Three-Fifths Compromise in 1787. This compromise was part of the U.S. Constitution and reflected the contentious issue of slavery in the early United States. The 14th Amendment, ratified in 1868, granted full citizenship and equal protection under the law to all persons born or naturalized in the U.S., effectively nullifying the three-fifths clause.