The United States shares a border with Mexico that is around 2,000 miles in length, with around 670 miles of border wall comprising a number of different kinds of barrier. NBC News says that lawmakers are hoping to be able to add another 700 miles of wall to the border to keep out undocumented immigrants.
The US Border Patrol website says that there is a great amount of variance in the nature of the barriers that have been placed on the US-Mexico border. “In the urban areas these barriers may be doubled to include a ‘secondary’ barrier with a ‘no man’s land’ between,” the website, which is maintained by Border Patrol supporters, says. “In some of the more violent areas populated by violent gangs or drug cartels, the barrier has been improved with a third obstacle – usually another fence.”
Many different kinds of barrier protect the main borders between the United States and Mexico, while in certain areas there are no barriers at all. In other places the materials used to construct the barriers include railroad rail, corrugated steel plates, three-wire cattle fence, square tubing and even crushed motor vehicles.
Secondary borders, which are not always present, include chain-linked fence, expanded metal fence, bollards and concrete. In the three-year period between 2006 and 2009, $2.4bn was spent by US Customs and Border Protection to complete 670 miles of border fence to prevent illegal immigration. The 2016 presidential nomination race has been dominated by talk of expanding the wall.