Following the War of 1812, Britain and the U.S. agreed to set the 49th parallel as the border from the Lake of the Woods in the east to the Rocky Mountains in the west.
The border is a "mathematical" line that often defies local geography, cutting through watersheds, mountains, and forests. 49th Parallel
The use of the 49th parallel as a border was not the result of a single event but a series of 19th-century treaties: Following the War of 1812, Britain and the U
A notable exception occurs at Vancouver Island, where the border swings south to ensure the entire island remains British. Geographic and Cultural Impact Following the War of 1812