The United States – Canada border, is the longest international border in the world between two countries. The terrestrial boundary (including portions of maritime boundaries in the Great Lakes, and on the Atlantic, Pacific, and Arctic coasts) is 8,891 kilometers (5,525 mi) long, of which 2,475 kilometers (1,538 mi) is Canada’s border with Alaska.
The contiguous U.S. – Canadian Border Overlaid on Europe
The total length of the United States – Mexico border is 3,145 kilometers (1,954 miles).
The contiguous U.S. – Mexican border distance in straight line over Europe