Who was the U.S. president in 1845 who aimed to resolve the Oregon boundary dispute and expand the nation?

James K. Polk, who served as president from 1845 to 1849, is recognized for his expansionist policies and for addressing the Oregon boundary dispute. Polk was a strong proponent of Manifest Destiny, the belief that the United States was destined to expand across the North American continent.

During his presidency, he successfully negotiated the Oregon Treaty with Great Britain in 1846, which settled the boundary between the U.S. and British North America at the 49th parallel. This resolution of the Oregon dispute not only fulfilled a significant goal of his administration but also exemplified Polk's commitment to territorial expansion.

Polk's administration also oversaw the acquisition of a vast amount of territory through the Mexican-American War, further solidifying his legacy as a president focused on expanding the nation. His actions during this period were pivotal in shaping the future of the United States, confirming his role as a key figure in this era of American history.