What was meant by 5440 or bust?

Answer 1

"5440 or Bust" was a slogan associated with the 1844 presidential campaign of James K. Polk and the expansionist sentiment of the time, particularly regarding the Oregon Territory. The phrase referred to the latitude line of 54 degrees, 40 minutes north, which was seen as the desired northern boundary of U.S. territory in Oregon. Supporters believed in aggressively pursuing this claim, leading to tensions with Britain, which controlled parts of the territory. Ultimately, the slogan encapsulated the era's Manifest Destiny ideology, advocating for the westward expansion of the United States.