A faulty 18th century map led to the unusual bump along the northern border of the U.S., ... Minnesota's Northwest Angle, ... made in 1783 during the Treaty of Paris.

In the Webster-Ashburton Treaty (1842), they agreed on the boundaries that shaped the Northwest Angle. Joint American-British boundary commissions determined the angle’s precise boundaries.

The 1855 treaty ceded a swath of land in northern and central Minnesota, and the 1855 Treaty Authority is composed of the beneficiaries of that treaty, including several Bemidji-area Ojibwe bands.