parts of these states made up the mexican border district
Mexico–United States border The U.S. states along the border, from west to east, are California, Arizona, New Mexico, and Texas. The Mexican states along the border are Baja California, Sonora, Chihuahua, Coahuila, Nuevo León, and Tamaulipas.
Texas Texas (/ˈtɛksəs/, locally /ˈtɛksɪz/;[9] Spanish: Texas or Tejas [ˈtexas]) is the second largest state in the United States by both area and population. Geographically located in the South Central region of the country, Texas shares borders with the U.S. states of Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the west, and the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the southwest, while the Gulf of Mexico is to the southeast.