U.S.-Canadian border established west of the Rocky Mountains | June 15, 1846 | HISTORY

Representatives of Great Britain and the United States sign the Oregon Treaty, which settles a long-standing dispute with Britain over who controlled the Oregon territory. The treaty established the 49th parallel from the Rocky Mountains to the Strait of Georgia as the boundary between the United States and British Canada. The United States gained formal control over the future states of Oregon, Washington, Idaho and Montana; and the British retained Vancouver Island and navigation rights to part of the Columbia River.