The Oregon Treaty is signed in Washington, D.C. by Representatives of Great Britain and the United States, establishing the U.S.-Canadian border at the 49th parallel and settling a long-standing dispute with Britain over who controlled the Oregon territory.
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. Tribes were not consulted as the 49th Parallel becomes the boundary. so many Native people on either side of the line wake up in a different country, living under different laws than those they knew the night before. More
By Kmusser - Own work, CC BY-SA 2.5