The Louisiana Purchase, the Convention of 1818, the Webster-Ashburton treaty, and the Adams Onis treaty were all about the changing American border. The Louisiana Purchase was the purchase of the territory owned by the French in 1803. This relates to the Adams Onis treaty of 1819 because it was the cession of Florida into the United States in return for settling the boundary between new Spain (Mexico) and the new U.S. territory acquired in the Louisiana Purchase. Although the Convention of 1818 and the Webster-Ashburton treaty were not about acquisition of new territory, they both settled border disputes between the Americans and the British. The convention of 1818 decided that the 49th parallel would be the boundary from Lake of the Woods (in present-day northern Minnesota, southwestern Ontario, and southeastern Manitoba) west to the Rocky Mountains (in present-day Montana and Alberta). This was a kind of precursor to the Webster-Ashburton treaty which reaffirmed what was decided in the Convention of 1818, as well as, resolving the Maine-New Brunswick border and establishing the boundary between Lake Superior and Lake of the Woods.