The international border between Mexico and the United States runs from San Diego, California, and Tijuana, Baja California, in the west to Matamoros, Tamaulipas, and Brownsville, Texas, in the east. It traverses a variety of terrains, ranging from major urban areas to inhospitable deserts. From the border crossing at El Paso, Texas, and Ciudad Juárez, Chihuahua, to the east, it follows the course of the Rio Grande (Río Bravo del Norte) to the Gulf of Mexico; from the same binational conurbation westward to the Pacific Ocean, it crosses vast tracts of the Sonoran and Chihuahuan Deserts, the Colorado River Delta, and the northernmost tip of the Baja California Peninsula.

The border's total length is 1,951 miles (3,141 km), according to figures given by the IBWC. It is the most frequently crossed international border in the world, with some 350 million people crossing (legally) every year.

Geography

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In the United States, Texas has the longest stretch of the border of any state, while California has the shortest. In Mexico, Chihuahua has the longest border, while Nuevo León has the shortest.

The international border between the United States and Mexico extends over 1,952 miles (3,141 km). The boundary follows the middle of the Rio Grande — according to the 1848 Treaty of Guadalupe Hidalgo between the two nations, "along the deepest channel" — from its mouth on the Gulf of Mexico a distance of 1,254 miles (2,019 km) to a point just upstream of El Paso, Texas, and Ciudad Juárez, Chihuahua. It then follows an alignment westward overland and marked by monuments a distance of 533 miles (858 km) to the Colorado River. Thence it follows the middle of that river northward a distance of 24 miles (38 km), and then it again follows an alignment westward overland and marked by monuments a distance of 141 miles (226 km) to the Pacific Ocean. The region along the boundary is characterized by deserts, rugged mountains, abundant sunshine and by two major rivers — the Colorado River and the Rio Grande (Río Bravo del Norte) — which provide life-giving waters to the largely arid but fertile lands along the rivers in both countries.

The total population of the borderlands — defined as those counties and municipios lining the border on either side — stands at some 12 million people.

From west to east, the border city twinnings and border crossings include the following:

• San Diego, California – Tijuana, Baja California
• Otay Mesa, California
• Tecate, Baja California
• Calexico, California – Mexicali, Baja California
• San Luis, Arizona – San Luis Río Colorado, Sonora
• Lukeville, Arizona – Sonoita, Sonora
• Sasabe, Arizona – Altar, Sonora
• Nogales, Arizona – Nogales, Sonora
• Naco, Arizona – Naco, Sonora
• Douglas, Arizona – Agua Prieta, Sonora
• Antelope Wells, New Mexico – Berrendo, Chihuahua
• Columbus, New Mexico – Palomas, Chihuahua
• Santa Teresa, New Mexico – San Geronimo, Chihuahua
• El Paso, Texas – Ciudad Juárez, Chihuahua
• Presidio, Texas – Ojinaga, Chihuahua
• Del Rio, Texas – Ciudad Acuña, Coahuila
• Eagle Pass, Texas – Piedras Negras, Coahuila
• Laredo, Texas – Nuevo Laredo, Tamaulipas
• McAllen, Texas – Reynosa, Tamaulipas
• Brownsville, Texas – Matamoros, Tamaulipas.

  The U.S. states along the border, from west to east, are:

  California, Arizona, New Mexico, and Texas.

  The Mexican states are:

  Baja California, Sonora, Chihuahua, Coahuila, Nuevo León, and Tamaulipas.

  History

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  With the exception of a small number of minor Rio Grande border disputes, since settled, the current course of the border was finalized by the 1848 Treaty of Guadalupe Hidalgo and the 1853 Gadsden Purchase. Whether the border between Mexico and the breakaway Republic of Texas followed the Rio Grande or the Nueces River further north was an issue never settled during the existence of that Republic, and the uncertainty was one of the direct causes of the 1846–48 Mexican-American War. An earlier agreement, signed during the Mexican War of Independence by the United States and Imperial Spain, was the 1819 Adams-Onís Treaty, which defined the border between the republic and the colonial empire following the Louisiana Purchase of 1804.

  For a detailed history of water-related agreements along the border since the signing of the 1848 Treaty, see International Boundary and Water Commission.

  Security issues

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  The U.S.–Mexico border has the highest number of both legal and illegal crossings of any land border in the world. Besides the closeness of the two countries, differences in living standards on the two sides of border is the primary driving force behind these migratory flows. A large percentage of the border is left virtually unguarded, except by a small number of patrolling agents of the U.S. federal government.

  For a period of time in the 1990s U.S. Army personnel were stationed along the U.S.-Mexico border to help stem the flow of illegal aliens and drug smugglers. These military units brought their specialized equipment such as FLIR infrared devices,and helicopters. In conjunction with the U.S. Border Patrol, they would deploy along the border and, for a brief time, there would be no traffic across that border which was actively watched by "coyotes" paid to assist border crossers. The smugglers and the alien traffickers simply ceased operations over the one hundred mile sections of the border sealed at a time. It was very effective but temporary as the illegal traffic resumed as soon as the military withdrew. After the September 11, 2001 attacks the United States looked at the feasability of placing soldiers along the U.S.-Mexico border as a security measure. Some believe the whole U.S.-Mexico border could be sealed with as few as 100 helicopters equipped with FLIR (forward looking infrared) scopes, and a few hundred men equipped with state of the art sensors, scopes and other electronics. Opposition says this is a violation of Posse Comitatus ignoring the fact that protecting against invasion is precisely what the armed forces are supposed to do and the army patroled the border for more than 46 years after the passage of the Posse Comitatus act. [http://www.renewamerica.us/columns/zieve/060713 Others, perhaps more realistic, believe that you could never completely close the border but could put a serious dent in illegal cross border traffic with a more robust military presence and a larger more pro-active Border Patrol.

  Each state in the United States has a National Guard organization that could, in principal, be placed on the border at a state governor's discretion to assist with border security; many states also have a backup to the National Gurard called the State Defense Force that could, in an emergency, also be activated for this purpose. Arizona and New Mexico have currently declared the counties that border Mexico to be under serious duress caused by uncontrolled illegal immigrant traffic, thereby enabling governors to deploy National Guardsmen to the international border. Arizona has exercised this option but New Mexico has not. In May 2006, President Bush announced a plan whereby up to 6,000 National Guardsmen would help build facilities on the border to assist the Border Patrol with tactical and technical measures but not enforcement duties. Of course this plan has stirred controversy by those wanting less border security not more. In California, Governor Arnold Schwarzeneggar initially denied Bush's request to deploy 3,000 National Guard troops to the California-Baja California border. Later Schwarzenegger changed his mind after being reassured of reimbursement and replacement if they are needed elsewhere and deployed over 1600 California National Guard troops to the border. It is estimated that over a million people cross the border illegally each year, most are Mexicans. The rest are labeled "Other Than Mexicans" (OTM), of whom a majority are Central Americans. An increaseing number of foreigners from Latin America, Asia and Europe are first flying to Mexico and then illegally crossing the border. Border Patrol activity is concentrated around big border cities such as San Diego and El Paso which do have extensive border fencing. This means that the flow of illegal immigrants is diverted into rural mountainous and desert areas, leading to a significant number of deaths. Attempts to complete the construction of the United States Mexico barrier have faced stiff opposition from the Mexican government, various U.S.-based Chicano organizations who all want essentially an uncontrolled border. About 45% of all agricultural laborers in the United States are unauthorized immigrants, according to migration experts at the University of California, Davis. Agricultural work is the only categoy of work that illegal immigrants fill that could not be easily filled by United States citizens. (See: [Illegal immigration to the United States)

  In December, 2005, the U.S. House of Representatives voted to build a separation barrier along parts of the border. A companion vote in the United States Senate on May 17, 2006 included a plan to blockade 860 miles of the border with vehicle barriers and triple-layer fencing. Appearing on the Comedy Central show The Colbert Report, Bay Buchanan, head of Team America, an immigration reduction political action committee, estimated that it would take less than six months to build a 2,000 mile, triple-layer fence and would cost roughly $1.5 - 3 billion. On the same show, Buchanan claimed that the 1990s-era border security program Operation Gatekeeper cut down unauthorized immigration by 90%. Similar results are predicted for a wall covering the entire border, which proponents hope will reduce illegal drug smuggling and illegal immigration drastically.

  According to Dr. Douglass Massey of the pro-immigration Cato Institute (Smoke and Mirrors: U.S. Immigration Policy in the Age of Globalization, Russel Sage, 2001) and other experts, the efforts to curtail illegal immigration by means of security has done nothing but redirect the migration flows into the most desolate and desertic areas of the border, thus increasing the mortality rate of illegal immigrants. Furthermore, the security measures prevent the migrants from re-entering Mexico and then returning, as they had done in the past. Instead, they remain in the U.S. for longer periods of time and eventually bring their families with them. President Bush has presented an initiative to reinstate a Guest Worker Program or expand the H-2B program to fill the perceived needs of labor for some areas of the U.S. and, at the same time, has pushed to strengthen the security measures at the border to stop suspected illegal immigrants, terrorists and narcotics dealers from entering the U.S. How much of this is again "Smoke and Mirrors" is unknown.

  See also

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  • United States-Mexico barrier
  • United States Border Patrol
  • U.S. Customs and Border Protection
  • Rio Grande border disputes
  • Border blaster
  • New River (California)
  • Border Field State Park
  • H.R. 4437
  • S. 2611

  References

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  • Trans-Border Institute
    
    

  Sources

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  Parts of this article have been adapted from The International Boundary and Water Commission, Its Mission, Organization and Procedures for Solution of Boundary and Water Problems, a public domain publication of the United States Government.

  Borders | Geography of the United States | Geography of Mexico | Mexico and the United States | Boundaries of U.S. states

  Граница между САЩ и Мексико | Frontera entre Estados Unidos y México | Grens tussen Mexico en de Verenigde Staten | Государственная граница между США и Мексикой