of actual geography in the boundary agreed to in the 1783 Treaty of Paris, which ended the American Revolutionary War. The earlier treaty had placed the boundary between the United States and British North America along a line extending westward from the Lake of the Woods to the Mississippi River. The parties did not realize that the river did not extend that far north and so such a line would never meet the river. In fixing the problem, the 1818 treaty created a pene-enclave of the United States, the Northwest Angle, the small section of the present state of Minnesota that is the only part of the United States apart from Alaska that lies north of the 49th parallel. Article III provided for joint control of land in the Oregon Country for ten years. Both could claim land and were guaranteed free navigation throughout. Article IV confirmed the Anglo-American Convention of 1815, which regulated commerce between the two parties, for an additional ten years. Article V agreed to refer differences over a US claim arising from the Treaty of Ghent, which ended the War of 1812, to "some Friendly Sovereign or State to be named for that purpose." The claim in question was for the return of or compensation for American slaves who had escaped to British-controlled territory or Royal Navy warships when the treaty was signed. The article in question was about handing over property, and the US government claimed that the slaves were the property of its citizens. Article VI established that ratification would occur within six months of signing the treaty. History The treaty was negotiated for the US by Albert Gallatin, ambassador to France, and Richard Rush, minister to the UK; and for the UK by Frederick John Robinson, Treasurer of the Royal Navy and member of the privy council, and Henry Goulburn, an undersecretary of state. The treaty was signed on October 20, 1818. Ratifications were exchanged on January 30, 1819. The Convention of 1818, along with the Rush–Bagot Treaty of 1817, marked the beginning of improved relations between the British Empire and its former colonies, and paved the way for more positive relations between the US and Canada although repelling a US invasion was a defense priority in Canada until 1928. Despite the relatively friendly nature of the agreement, it resulted in a fierce struggle for control of the Oregon Country for the following