As they approached the Rio Grande from the south, Spanish explorers in the colonial period viewed two mountain ranges rising out of the desert with a deep chasm between. This site they named El Paso del Norte (the Pass of the North), and it became the location of two future border cities, Ciudad Juárez on the south or right bank of the Rio Grande and El Paso, Texas, on the opposite side of the river. The arrival of the first Spanish expedition at the Pass of the North in 1581 marked the beginning of more than 400 years of history in the El Paso area. It was followed in 1598 by the colonizing expedition under Juan de Oñate. On April 30, 1598, in a ceremony at a site near present San Elizario, Oñate took formal possession of the entire territory drained by the Rio Grande and brought Spanish civilization to the Pass of the North.
In 1659 Fray García de San Francisco founded Nuestra Señora de Guadalupe Mission, which still stands in downtown Ciudad Juárez, the oldest structure in the El Paso area. The Pueblo revolt of 1680 sent Spanish colonists and Tigua Indians of New Mexico fleeing southward to take refuge at the Pass. By 1682 five settlements were founded south of the river-El Paso del Norte, San Lorenzo, Senecú, Ysleta, and Socorro, thus providing the Pass with a concentration of population from that time to the present. A presidio was built in 1684. The area became a trade center on one of the historic caminos reales, or royal highways, and agriculture flourished, particularly the vineyards, producing wine and brandy that ranked in quality with the best in the realm.
When Mexico won its independence from Spain in 1821 the El Paso area and what is now the American Southwest became a part of the Mexican nation. The municipal council of El Paso del Norte granted land north of the Rio Grande to Juan María Ponce de León, and it became a thriving agricultural and ranching enterprise; his land is now the site of downtown El Paso. With the outbreak of hostilities between the United States and Mexico in May 1846, Col. Alexander Doniphan and his Missouri volunteers defeated the Mexicans at the battle of Brazito, entered El Paso del Norte, and occupied the city of Chihuahua in early 1847. The Treaty of Guadalupe Hidalgo of February 2, 1848, fixed the boundary between the two nations at the Rio Grande, and thus El Paso del Norte, the future Ciudad Juárez, became a bordertown.
By late 1849, aided by the gold rush to California, five settlements had been established by Anglo-Americans north of the river, one of them, known as Franklin, on the ranch of former proprietor, Ponce de León. In 1859, however, pioneer Anson Mills named this settlement El Paso, thus generating considerable confusion that lasted for almost thirty years.
During the period of the French intervention in Mexico the republican cause under the leadership of Benito Juárez took refuge in El Paso del Norte in August 1865 and remained there for almost a year. With the aid of American arms and munitions the tide began to turn in favor of the Juárez republicans, who returned to Mexico City in triumph in 1867. On September 16, 1888, El Paso del Norte was renamed Ciudad Juárez, and thus the historic name El Paso became the sole possession of the bustling little railroad town at the western tip of Texas.