How did the US acquire the Oregon Territory in 1846?

Along with territorial disputes with Spain and Mexico over the Southwest, the fate of the Oregon Territory was one of the major diplomatic issues of the first half of the 19th ... In 1823 President Monroe promulgated his doctrine , which put Russia on notice that the United States did not accept Russian attempts at monopoly. read more

The Oregon Country had been claimed by various nations, including Spain, Russia, Great Britain and the U.S., but the U.S. and Great Britain soon made a joint occupation agreement, in 1818, until it was superseded by the Oregon Treaty of 1846, which established it as a U.S. state at the 49th parallel. read more

In 1846, the Oregon boundary dispute between the U.S. and Britain was settled with the signing of the Oregon Treaty. The British gained sole possession of the land north of the 49th parallel and all of Vancouver Island, with the United States receiving the territory south of that line. read more

Originally Spain, Great Britain, Russia, and the United States claimed the territory. In 1819, under terms of the Transcontinental Treaty, Spain ceded its claims to the territory to the United States. read more