USA HISTORY

Detailed explanation-1: -In June 1846, the Senate, preoccupied with war against Mexico, quickly approved the Oregon Treaty with Britain, setting the boundary at the 49th parallel.

Detailed explanation-2: -The agreement extended the border along the 49th parallel to the Pacific Ocean but kept Vancouver Island within British North America. It was also agreed that British subjects living in the Oregon Territory south of the 49th parallel would retain navigation rights on the Columbia River.

Detailed explanation-3: -In 1834 the Methodists, headed by Jason Lee, established the first permanent settlement in the Willamette River valley. The migrations that carved the deep wagon wheel ruts still visible in the Oregon Trail began in the early 1840s. After 1838, U.S. claims and rights to the region were constantly before Congress.

Detailed explanation-4: -The U.S. claim was based on the explorations of Lewis and Clark and on the establishment of trading posts set up by John Jacob Astor’s Pacific Fur Company, such as Astoria at the mouth of the Columbia River. Great Britain based its claim, in part, on James Cook’s exploration of the Columbia River.