MAP 13.1 Territorial Conflict in Oregon, 1819–1846
As thousands of American settlers poured into the Oregon Country in the early 1840s, British authorities tried to keep them south of the Columbia River. However, the migrants — and fervent expansionists — asserted that Americans could settle anywhere in the territory, raising the prospect of armed conflict. In 1846, British and American diplomats resolved the dispute by dividing most of the region at the forty-ninth parallel while giving both nations access to fine harbors (Vancouver and Seattle) through the Strait of Juan de Fuca.