"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."
Replaced by: Amendment 14. Section 2. "Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State..."
Comment: This provision is called the Three-fifths Clause; it is a rule for counting slaves. At the time many people believed that slaves were just property, not persons, and should not be counted. The North resisted counting slaves for many reasons (e.g., it might cause a reason to have more slaves). As a result, deadlock ensued. In Federalist No. 54, Madison argued that "we must deny the fact, that slaves are considered merely as property, and in no other respect whatever as persons." He did write, however, that the issue of slaves was a "peculiar" one. In the end, he stated that slaves retain both qualities (personhood and property). In any event, a provision linking direct taxes and representation with apportionment provided a compromise. Slaves were counted as 3/5ths for representation, which did not benefit the South as much had each slave been counted as a whole person; however, the South benefited from the 3/5ths rule for direct tax apportionment, which reduced their total tax liability. The silver lining in this mess is that in the end the Constitution did (in some way) recognize slaves as persons, and not merely as property.
Primary Source. The Heritage Guide to the Constitution.
Federalist Paper No 54