The Constitution was a document based upon compromise: between larger and smaller states, between proponents of a strong central government and those who favored strong state governments, and, above all, between northern and southern states. Of all the compromises on which the Constitution rested, perhaps the most controversial was the Three-Fifths Compromise, an agreement to count three-fifths of a state's slaves in apportioning Representatives, Presidential electors, and direct taxes.
The three-fifths figure was the outgrowth of a debate that had taken place within the Continental Congress in 1783. The Articles of Confederation had apportioned taxes not according to population but according to land values. The states consistently undervalued their land in order to reduce their tax burden. To rectify this situation, a special committee recommended apportioning taxes by population. The Continental Congress debated the ratio of slaves to free persons at great length. Northerners favored a 4-to-3 ratio, while southerners favored a 2-to-1 or 4-to-1 ratio. Finally, James Madison suggested a compromise: a 5-to-3 ratio. All but two states--New Hampshire and Rhode Island--approved this recommendation. But because the Articles of Confederation required unanimous agreement, the proposal was defeated. When the Constitutional Convention met in 1787, it adopted Madison's earlier suggestion.
The taxes that the Three-Fifths Compromise dealt with were "direct" taxes, as opposed to excise or import taxes. It was not until 1798 that Congress imposed the first genuine direct taxes in American history: a tax on dwelling-houses and a tax on slaves aged 12 to 50.
The Three-Fifths Compromise greatly augmented southern political power. In the Continental Congress, where each state had an equal vote, there were only five states in which slavery was a major institution. Thus the southern states had about 38 percent of the seats in the Continental Congress. Because of the 1787 Three-Fifths Compromise, the southern states had nearly 45 percent of the seats in the first U.S. Congress, which took office in 1790.
It is ironic that it was a liberal northern delegate, James Wilson of Pennsylvania, who proposed the Three-Fifths Compromise, as a way to gain southern support for a new framework of government. Southern states had wanted representation apportioned by population; after the Virginia Plan was rejected, the Three-Fifths Compromise seemed to guarantee that the South would be strongly represented in the House of Representatives and would have disproportionate power in electing Presidents.
Over the long term, the Three-Fifths Compromise did not work as the South anticipated. Since the northern states grew more rapidly than the South, by 1820, southern representation in the House had fallen to 42 percent. Nevertheless, from Jefferson's election as President in 1800 to the 1850s, the three-fifths rule would help to elect slaveholding Presidents. Southern political power increasingly depended on the Senate, the President, and the admission of new slaveholding states.
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 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. The actual enumeration shall be made within three years after the first meeting of the Congress of the United States, and within every subsequent term of ten years, in such manner as they shall by law direct. The number of representatives shall not exceed one for every thirty thousand, but each state shall have at least one representative.... [In 1929, Congress fixed the total number of Representatives at 435; currently, there is one Representative for about every 519,000 persons].