More officially, it’s the Aroostook War a.k.a. the Pork and Beans War or Madawaska War of 1838-39 over the international boundary between Maine and the British province of New Brunswick.
Although militia units were called out, no actual fighting took place.
Well, there was a skirmish between armed lumbermen, the Battle of Caribou, in 1838.
The dispute was settled by negotiations by British diplomat Baron Ashburton and U.S. Secretary of State Daniel Webster in an 1842 treaty.
Without getting into the myriad details, it is how the Aroostook County towns of Fort Kent and Fort Fairfield got their full names. And most but not all of the disputed territory wound up in the USA, with Aroostook County being formed in 1840.
Reported casualties came from accidents and disease rather than actual combat.
Jnana's Red Barn 