Video: 'Oregon Territory - Manifest Destiny Choose Your Own Adventure'

(Monday, August 14, 1848) — The Oregon Territory was established today after Congress passed and President James K. Polk signed the Act to Establish the Territorial Government of Oregon, encompassing all of the present-day states of Idaho, Oregon and Washington, as well as those parts of present-day Montana and Wyoming west of the Continental Divide.

Its southern border was the 42nd parallel north (the boundary of the Adams-Onis Treaty of 1819), and it extended north to the 49th parallel.