The slogan encapsulated the expansionist aims of some Americans in the 1840s regarding the Oregon Territory. It referred to the latitude 5440′, which was the northern boundary desired by these expansionists for the United States’ claim in the Pacific Northwest. Failure to secure this boundary, according to proponents, would warrant military action against Great Britain, which also claimed the territory.
This expression gained prominence during the 1844 presidential election, serving as a potent symbol of Manifest Destiny and American nationalism. It reflected a belief in the United States’ right to expand its territory and influence across the North American continent. While the specific boundary demanded was not ultimately achieved through negotiation, the slogan fueled popular support for expansionist policies and contributed to the eventual resolution of the Oregon boundary dispute.