On the old
US census slaves were counted as
three fifths of a
person.
The North (which had few
slaves ) felt that
the south should not
count them at all since they could not
vote,
travel, or do much of anything that as not their
master's will. The three fifths
compromise allowed the
south to gain an advantage in the number of
representatives it could send to the
house without acknowledging the
humanity of a large number of its
citizens.
U.S. Constitution as ratified in 1787. Article I, section 2 stated, among other things:
Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons.