On April 20, 1817, the Rush-Bagot Treaty was signed between the U.S. and Great Britain – one of the first acts of Monroe’s first presidential term. The treaty regulated naval armaments on the Great Lakes and Lake Champlain after the War of 1812, demilitarizing the border between the U.S. and Canada. It created the world’s longest east-west boundary (5,527 miles), which is also said to be the world’s largest demilitarized zone.
Read more about the Rush-Bagot Treaty.