USA HISTORY

Detailed explanation-1: -Originally claimed by several countries (see Oregon Country), the region was divided between the UK and the US in 1846. When established, the territory encompassed an area that included the current states of Oregon, Washington, and Idaho, as well as parts of Wyoming and Montana.

Detailed explanation-2: -The United States and Great Britain signed the Treaty of Oregon on June 15, 1846, ending 28 years of joint occupancy of the Pacific Northwest. The treaty established the 49th parallel as the border between the two countries.

Detailed explanation-3: -In 1846 Britain and the United States signed the Oregon Treaty, extending the international border between the U.S. and what would become Canada along the 49th parallel to the Strait of Georgia, and then out the Strait of Juan de Fuca.

Detailed explanation-4: -The U.S. and Great Britain entered into the Oregon Treaty of 1846, an agreement that divided the Oregon Territory along the 49th parallel and gave Great Britain all of Vancouver Island.