What was the purpose of 54' 40 or fight?

"54' 40 or Fight!" was a slogan used in the mid-19th century during the Oregon boundary dispute between the United States and Britain. It referred to the latitude line of 54 degrees 40 minutes, which some American expansionists claimed should be the northern boundary of the U.S. territory in the Pacific Northwest. The slogan encapsulated the desire for aggressive expansion and was part of a broader manifest destiny ideology, ultimately leading to the negotiation of the Oregon Treaty in 1846, which settled the boundary at the 49th parallel.