Along the 3,145 km United States and Mexico border, we find different types of fences, walls, and fortifications. Throughout the 20th century small type fences have been built along the border, to stop illegal immigration and drug trafficking. Only after 9/11 in 2006 President Bush signed the Secure Fence Act to authorize the building of a new border wall with 1,126 km of double tier fence. The fence is a mesh woven so tightly that feet and fingers cannot grab hold, with two meters of concrete underground against tunnelling, and steel pylons to stop trucks from bursting through. The border is patrolled by 18,516 Border Patrol agents, 270 airplanes, including 7 Predator drones. Today only 60 km double tier fence has been built, 560 km of single tier fence, and 490 km of vehicle barriers.

Border length: 3,145 km
Established: 1884
Fence height: 5,48 m (18 ft)