The Texas-Mexico border makes up 1,254 miles of the 1,900-mile-long U.S.-Mexico border.
The vast, mostly rural expanse stretches from El Paso in the West to Brownsville in the Southeast and is delineated by the Rio Grande River.
Border communities in Texas are some of the poorest regions of the state and the nation. If Texas border counties comprised the 51st state, it would rank last in per capita personal income and first in poverty and unemployment, according to Texas Borderlands: Frontier to the Future, a 2009 report by state Sen. Eliot Shapleigh, D-El Paso.
The border population is also expanding rapidly, according to the report, with El Paso-Juarez increasing some 38 percent in the 1990s, Laredo-Nuevo Laredo growing 48 percent and McAllen-Reynosa jumping 38 percent.
El Paso-Juarez is among the largest border metroplexes in the world. Together, the two cities, which are separated only by the Rio Grande, have a population of more than 2 million.
Laredo, directly across from Nuevo Laredo, is the largest inland port in the United States.
The border has been the center of much controversy beginning with the Sept. 11, 2001 terrorist attacks. Some worried that the porous U.S.-Mexico border would be used by terrorists to transport weapons of mass destruction into the country.
The concerns prompted Congress to enact tougher security regulations that for the first time in 2009 required U.S. citizens to show a passport to return from Mexico. The U.S. Border Patrol also began hiring thousands of additional agents to patrol the southern border.
Concerns about security and about illegal immigration also resulted in the Secure Fence Act of 2006 that required the construction of 700 miles of fencing along the U.S.-Mexico border.
In Texas, the fencing generated local outrage, especially in the Rio Grande Valley, where some residents filed ultimately unsuccessful lawsuits to stop the construction.
The increasingly violent Mexican war against drug cartels has also prompted security worries about spillover into Texas border communities. The death toll for 2009 had already surpassed 2,000 in Juarez in October of that year.