49th Parallel Today
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.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. 49th Parallel
A notable exception occurs at Vancouver Island, where the border swings south to ensure the entire island remains British. Geographic and Cultural Impact The use of the 49th parallel as a