March 2, 1807: The U.S. Congress passes the Act Prohibiting Importation of Slaves.
One stipulation of the United States Constitution ensured that the country’s part in the international slave trade would stand for twenty years after the Constitution’s ratification. According to Section 9, slave importations would “not be prohibited by the Congress prior to the Year one thousand eight hundred and eight.” On March 2, 1807, the House and Senate approved a bill that was to go into effect in 1808 which declared that
from and after the first day of January, one thousand eight hundred and eight, it shall not be lawful to import or bring into the United States or the territories thereof from any foreign kingdom, place, or country, any negro, mulatto, or person of colour, with intent to hold, sell, or dispose of such negro, mulatto, or person of colour, as a slave, or to be held to service or labour.
By 1800 nearly 900,000 slaves lived in the United States. Importation had continued on into the new century, even as the country’s founding fathers attempted to awkwardly reconcile that which they considered a “cruel war against human nature itself,” their own ownership of slaves, and the liberal ideals that philosophically undergird the country’s founding. Some Americans did recoil at the horrors of the Middle Passage, which seemed a relic of a less civilized century. Still others (or the very same individuals who proclaimed their moral disgust) had practical reasons for supporting an end to importation. At the Constitutional Convention, Charles Pinckney of South Carolina pointed out that George Mason’s state of Virginia would benefit from an end to slavery, because “her slaves will rise in value, and she has more than she wants.” Oliver Ellsworth observed that “slaves multiply so fast in Virginia and Maryland that it is cheaper to raise than import them.” They could not have overestimated the future vitality of the domestic slave trade, which exported a million black slaves from primarily the upper South into the expanding plantation-kingdoms of the deep South.
In the Chesapeake, tobacco and the slave labor required to cultivate that staple were growing increasingly unprofitable and unappealing to the point that planters could feel financially relieved, in addition to morally, when they weaned themselves off the institution. Even before 1808, the domestic slave trade was a booming enterprise, a system of enterprising enslavers, markets that economically integrated whole regions, black slaves fungible as currency and valuable as commodities; this was a trade so horrific - entailing broken families, forced 700-mile marches, iron chains and coffles - that historians dubbed this internal trade the “Second Middle Passage.”