What gave the U.S. larger claim than Britain to the Pacific Northwest?

Answer 1

One of the factors that gave the United States a larger claim than Britain to the Pacific Northwest was the exploration and expansion of American settlers in the region. The Lewis and Clark expedition in 1804-1806, as well as other expeditions and settlements by American pioneers, helped to establish a stronger American presence in the region.

Additionally, the Americans had a growing population and a desire for territorial expansion, which put pressure on Britain to negotiate a settlement over the disputed territory. Eventually, the Oregon Treaty of 1846 divided the Oregon Country along the 49th parallel, with the southern portion becoming part of the United States, while the northern portion remained British territory (later forming the Canadian province of British Columbia). This treaty solidified American control over the Pacific Northwest and gave them a larger claim than Britain in the region.