Mexico–United States barrier

The Mexico–United States barrier is a series of walls and fences aimed at preventing illegal crossings from Mexico into the United States. The barrier is not one continuous structure, but a grouping of short physical walls, secured in between with a “virtual fence” which includes a system of sensors and cameras monitored by the United States Border Patrol. As of January, 2009, U.S. Customs and Border Protection reported that it had more than 580 miles (930 km) of barriers in place. In contrast, the United States–Mexico border is 1,989 miles (3,201 km) long.