a city in Texas in the US, next to the Rio Grande and the border with Mexico. City (pop., 2000: 563,662), western Texas, U.S. Located on the Rio Grande river opposite Ciudad Juárez, Mex. , it is the largest of the U.S.-Mexican border cities. The area was the site of several missions from the 16th century; the first village was built on the site of El Paso in 1827. It became U.S. territory in 1848, when an army post was erected; the town was laid out in 1859. It grew slowly until 1881, when four railways arrived; in a decade El Paso's population increased more than tenfold. Spanish language and culture distinguish the modern city. The commercial and financial centre for an extensive trade territory, it is the site of the University of Texas at El Paso (1913) and Fort Bliss (home of the U.S. Army Air Defense Center); the White Sands Missile Range is nearby