Harry v. Decker & Hopkins (1818), a decision by the Supreme Court of Mississippi, and the first among southern states, to free a slave solely on the basis of prior residence in a free territory. The court held that any state may, through its Constitution, prohibit slavery within its boundaries, and also through its legislature, when not constrained by the Constitution; and that slaves residing in the Northwest Territory

Northwest Territory

The Territory Northwest of the River Ohio, more commonly known as the Northwest Territory, was an organized incorporated territory of the United States that existed from July 13, 1787, until March 1, 1803, when the southeastern portion of the territory was admitted to the Union as the state of Ohio...

 becomes free as per the Ordinance of 1787

Northwest Ordinance

The Northwest Ordinance was an act of the Congress of the Confederation of the United States, passed July 13, 1787...

, and may assert their rights in court.

Background

In 1787, the Virginian John Decker brought his slave Harry and two others to Vincennes in the Northwest Territory that is currently Indiana. They lived there until July of 1816 but moved to Mississippi with his slaves when the antislavery provisions of the Indiana state constitution, ratified on 29 June 1816, was to go into effect in July. Upon arrival the three slaves sued for their freedom, on the basis of the antislavery provisions in the Northwest Ordinance and the Indiana state constitution. Decker on the other hand argued that the treaty of cession between Virginia and the United States protected slavery in the territory. Decker also asserted that the Indiana Constitution could not end slavery there as it would violate that treaty of cession. Decker believed that the only liberating aspects of the Northwest Ordinance were only applicable to slaves brought into the territory after 1787, this was also the position of the Illinois Supreme Court until 1845.

Decision

The Supreme Court of Mississippi agreed that the treaty of cession protected the property of settlers living in the area at the time, but became superseded by the Ordinance of 1787. In the court's opinion the ordinance would, "defeat the great object of the general government," and be, "inadmissible upon every principle of legal construction." They also went on to opine that, "Slavery is condemned by reason, and the laws of nature. It exists and can exist only through municipal regulations."