El Camino Real de los Tejas was the main overland route from Mexico through Texas into Louisiana, a network of roads that shaped the region’s history and culture. Long before Europeans arrived, Native Americans established trade routes through the region that connected people and traditions and carried crops and goods. In the late 1600s, the Spanish called the local Caddo Indians Tejas and renamed these routes El Camino Real de los Tejas, extending and adapting them as soldiers reinforced Spanish claims and missionaries sought to convert Native Americans. Between 1686 and 1689, Alonso De León led four Spanish military explorations in search of La Salle’s French settlement, Fort St. Louis, likely using existing Native American routes and helping open the way for the first mission in East Texas, San Francisco de los Tejas, in 1690. The missions became a foundation for the Spanish presence in Texas and developed into towns and cities such as Nacogdoches, Crockett, and San Antonio. As settlers came from east and west, many Native groups including the Caddo and Ais were forced from their traditional homelands. Around 1823, immigrants from the United States began arriving in Mexican-held Texas and settling between the San Antonio and Brazos Rivers, and continued traffic along El Camino Real de los Tejas brought more Americans seeking opportunity and inexpensive farmland. By the time Texas declared independence from Mexico in 1836, more than 25,000 American immigrants lived in Texas. Made up of many routes, El Camino Real de los Tejas stretched across 2,500 miles, and parts of it remain in use today as Texas State Highway 21 and other highways in south and east Texas.