SLAVE TRADE SUPPRESSION In accordance with constitutional provision [Article I, Section 9], President Thomas Jefferson on March 2, 1807 signed an "Act to prohibit the importation of slaves into any port or place within the jurisdiction of the United States" after January 1, 1808. This act, of course, technically ended the Atlantic slave trade to the United States. After 1808, Congress passed numerous amendments and supplements to the law, including the institution of the death penalty for those convicted of breaking it. In addition, several international treaties (1824 and 1842) were entered into by the United States to defend against possible violations of the law.
Unfortunately, since Congress provided no special machinery to enforce these laws, the act of 1808 proved difficult to implement and, accordingly, the Atlantic slave trade to the United States continued on an illegal basis for the next fifty years. It was not until the late 1850's that effective federal action was taken to finally suppress the traffic in human cargo. During the administration of James Buchanan, for example, the enforcement of all slave trade legislation was centralized in the Department of the Interior, an administrative change usually credited to the succeeding Lincoln administration. Additionally, greatly increased congressional appropriations and a largely successful campaign to perfect naval enforcement of the laws did much to suppress the slave trade. Its final death knell, of course, was sounded by the cannons at Fort Sumter in 1861. See also: ATLANTIC SLAVE TRADE.