The United States shares a southern land border with Mexico that stretches 1,933 miles (3,111 kilometers) across California, Arizona, New Mexico, and Texas. To the north, the United States shares two land borders with Canada. The border separating Canada from the contiguous United States, which is also known as the International Boundary, extends for 3,987 miles (6,416 kilometers), while the border between Canada and the state of Alaska is 1,538 miles (2,475 kilometers) in length. Combined, the Canada–United States borders create the longest land border between any two countries in the world, one that is often described as the "world's longest undefended border" due to its lack of military outposts.
The livelihood of millions of Americans depends on the efficient...Read more