Slavery drove the framers to compromise their ideals with hard-headed politics. The slavery issue divided Madison’s Northern and Southern allies, and it threatened to unravel the possibility of a stronger national government. Many Northern delegates considered slavery morally indefensible. Many Southerners ardently defended it as essential for their region.1 Slavery linked the apportionment of seats in Congress to the scope of national government authority. If slaves counted in estimating the relative population size of the states, the slave states—Virginia, North and South Carolina, and Georgia—would gain an important advantage in Congress, and would have a strong incentive to support broad national powers. But if the delegates refused to count the slave population, these slave states would be at a severe political disadvantage, and might not ratify the Constitution at all.
The delegates could only get past their differences over slavery with a series of political compromises that underwrote slave states’ power. The compromise over representation allowed Southern states to count slaves as three-fifths of a person for the purposes of determining a state’s seats in the House of Representatives and its electoral votes for president. This compromise guaranteed that the South’s slave-owning whites would have a disproportionate influence in national policy-making. Other compromises ensured that slave states could continue to import slaves for a generation and would have the authority to recover their escaped slaves.
These compromises had tragic consequences for the nation. Almost four score years later, Abraham Lincoln said he considered slavery to be “a moral, social and political evil”—but in the next breath acknowledged “its actual existence amongst us and the difficulties of getting rid of it in any satisfactory way, and to all the Constitutional obligations which have been thrown about it.”2