Oregon Territory was created after the settlement in 1846 of a boundary dispute between the United States and Britain. It included the present states of Idaho, Oregon, and Washington and part of Montana and Wyoming. Before 1846, the Oregon Country, occupied jointly by the United States and Britain, included the area south of Alaska, north of California, and west of the Rocky Mountains. The 1846 settlement gave the United States the land south of the 49th parallel, except for Vancouver Island. The Oregon Country became a territory in 1848. Oregon was admitted to the Union on Feb. 14, 1859.
