"fifty-four forty or fight" referred to demands for american control of:

Oregon Territory. At the time, the border of the Oregon Territory existed almost up to the border of Russian Alaska in a joint territory controlled by the US and the UK. The area was well known for its natural resources including mining, timber and highly fertile areas for farming. This call was part of the general manifest destiny and the US call for domination of the continent from coast to coast.

What’s the question here?