In 1787, the US constitutional convention looked at the problem of counting its population. The population of a state determines the influence a state can take in a presidential election. The convention also looked at the problem of counting slaves: If they were counted, the state would have more power in the election, the taxes the state would have to pay to the government would also be higher. The Three-Fifths Compromise was that three out of every five slaves would be counted, in other words, black slaves were counted as three fifths of a human being. The compromise of counting "all other persons" as only three-fifths of their actual numbers reduced the representation of the slave states relative to the original proposals, but improved it over the Northern position. An inducement for slave states to accept the Compromise was its tie to taxation in the same ratio, so that the burden of taxation on the slave states was also reduced.
A contentious issue at the 1787 Constitutional Convention was whether slaves would be counted as part of the population in determining representation of the states in the Congress or would instead be considered property and, as such, not be considered for purposes of representation. Delegates from states with a large population of slaves argued that slaves should be considered persons in determining representation, but as property if the new government were to levy taxes on the states on the basis of population. Delegates from states where slavery had become rare argued that slaves should be included in taxation, but not in determining representation.
The proposed ratio was, however, a ready solution to the problem that arose during the Constitutional Convention. In amending the Articles, the North wanted slaves to count for more than the South did because the objective was to determine taxes paid by the states to the federal government. In the Constitutional Convention, the more important issue was representation in Congress, so the South wanted slaves to count for more than the North did.:397
Much has been said of the impropriety of representing men who have no will of their own.... They are men, though degraded to the condition of slavery. They are persons known to the municipal laws of the states which they inhabit, as well as to the laws of nature. But representation and taxation go together.... Would it be just to impose a singular burden, without conferring some adequate advantage?
- Finkelman, Paul (2013). "How The Proslavery Constitution Led To The Civil War". Rutgers Law Journal. 43 (3): 405. SSRN 2243060.
- Madison, James (1787). Hunt, Gaillard (ed.). 1787: The Journal of the Constitutional Convention, Part I. The Writings of James Madison. Vol. 3. G. P. Putnam's Sons (published 1902).
- Elliot, John, ed. (1866). The Debates In The Several State Conventions On The Adoption Of The Federal Constitution, As Recommended By The General Convention At Philadelphia, In 1787. Vol. 2. Philadelphia and Washington, D.C.: J.B. Lippincott & Co.; Taylor & Maury. p. 237.