Although the Oregon Treaty—dividing the Oregon Country between the United States and Great Britain at the 49th parallel—was signed in June 1846, securing American claims to what would become Oregon, Washington, Idaho, and parts of Montana and Wyoming, this image shows the signature page and President James K. Polk’s proclamation, issued on August 5, 1846, formally announcing the treaty’s ratification and implementation.
Polk’s formal announcement on August 5th brought a peaceful conclusion to a volatile geopolitical dispute that had pushed the United States and Great Britain to the absolute brink of a third war. For years, expansionist politicians had rallied the American public with the aggressive, nationalistic campaign slogan “Fifty-Four Forty or Fight!”, demanding the entirety of the Oregon Territory all the way to the southern border of Russian Alaska. Realizing that the nation was already deeply entangled in the Mexican-American War on its southern border, Polk wisely abandoned his aggressive rhetoric and chose pragmatism over pride, quietly compromising with the British at the 49th parallel to secure a massive, resource-rich empire for the United States without firing a single shot against the British Empire.
