Slavery Clauses in the U.S. Constitution

The U.S. Constitution was written at a convention that met in Philadelphia from May 25 until September 17, 1787. At the time, slavery was legal and a vibrant economic institution in eight states, while two (Massachusetts and New Hampshire) had abolished it, and three others (Pennsylvania, Rhode Island, and Connecticut) had passed gradual abolition acts. There were about 700,000 slaves in the nation, with more than 600,000 in Virginia, South Carolina, North Carolina, and Maryland. Virginia’s 300,000 slaves constituted just over 40 percent of the state, while South Carolina’s 107,000 slaves made up 43 percent of the state. Slaves were property and enormously valuable. They were also central to the southern economy. Indeed, with the exception of real estate, slaves represented the single most valuable form of privately held property in the nation. And, as people, they comprised more than a third of the entire population of the South. Not surprisingly, this important economic interest and this peculiar social relationship led to significant debates at the Constitutional Convention.

The issues of slavery affected discussion about the Constitution from the very first day of debates until the end of the convention. The final document did not use the word slave, because northern delegates feared that the use of the term would make ratification in their states more difficult. But slavery was embedded into the Constitution in many places and shaped the Constitution in at least five important ways. First, the delegates had to determine how slaves would be counted for purposes of representation. Naturally, southerners wanted to count all of them when allocating seats in Congress. Most northerners believed that slavery was deeply immoral and had no place in the allocation of power in a free country. How the Convention dealt with this issue would determine how power would be shared within the new government. In the end, the Convention compromised by counting slaves on a three-fifths basis. This compromise gave the South significant power in Congress and in the Electoral College.

The second area of debate concerned the power of Congress over commerce and the African slave trade. The document written in Philadelphia ultimately prevented Congress from interfering with the trade for at least twenty years. Third, the slaveholders at the convention—a majority of the delegates—insisted that the Constitution provide explicit federal protections for slavery. This was accomplished with clauses providing for the suppression of slave rebellions and a ban on export taxes, which southerners feared would be used to harm their slave-based agricultural economy. In addition to promises of federal protection, the slave owners at the convention insisted on guarantees that the states would also afford protection for their property. Thus, they prevailed upon the northern delegates to support a fugitive slave clause that would prohibit free states from emancipating fugitive slaves and instead guarantee that masters could capture their runaways. Finally, the Constitution created a government of limited powers that had no power over slavery in the states.

At no time did the Constitutional Convention consider giving the national government power to end slavery or even regulate it in the states where it existed. Numerous times during the convention the southern delegates made clear that they would not support the Constitution unless their slave property was protected from the general government. They gained this end through the overall structure of the Constitution. Thus, when he returned from the Convention, South Carolina’s most important delegate, General Charles Cotesworth Pinckney, proudly told his state legislature: “We have a security that the general government can never emancipate them, for no such authority is granted and it is admitted, on all hands, that the general government has no powers but what are expressly granted by the Constitution, and that all rights not expressed were reserved by the several states.”