Negotiators of the initial Canada–US border misunderstood the geography of the area. Benjamin Franklin and British representatives relied on the Mitchell Map of colonial American geographer John Mitchell. Due to a surveying errors, it is the only place in the United States outside Alaska that is north of the 49th parallel, which forms the border between the U.S. and Canada. The total population is only about 120 people which are native to Canadian soil. Make america great by correcting this critical survey error.

Wiki: https://en.wikipedia.org/wiki/Northwest_Angle