Santa Fe Trail, overland route, extending from western Missouri to Santa Fe, in present-day New Mexico, and used mainly for trade. The trail opened in 1821 and was in use almost continuously until 1880.

The trail, which was about 1,255 km (about 780 mi) long, began in Old Franklin, Missouri, traveled west to the Arkansas River, and followed the river southwest. The route then split into two branches. One route continued along the river to Bent’s Fort (now La Junta), Colorado, and then south through Raton Pass to Santa Fe. The second route cut across the Cimarron Desert to Santa Fe. The Cimarron Desert route was shorter and easier for the wagon parties than the mountainous Raton Pass, but travelers risked attacks by Native Americans and shortages of water. Other trails that were connected to the Santa Fe Trail included the Old Spanish Trail, which linked Santa Fe to Los Angeles, and the El Camino Real, which connected Santa Fe to Mexico City.

Before Mexico won its independence from Spain in 1821, the Spanish banned trade between Santa Fe and the United States. After independence, Mexico encouraged trade. In 1821 William Becknell, an American trader, traveled to Santa Fe where he traded his goods for gold, silver, and furs. In 1822 Becknell led the first wagonloads of goods into Santa Fe.

Soon many traders were traveling the Santa Fe Trail. In later years the trail was used frequently, with more than 2,000 wagons, in caravans of about 50, departing each spring from staging centers in Missouri. During the Mexican War, travel was restricted, but in 1848 trading resumed. Trade was limited again during the American Civil War (1861-1865), but by the late 1860s, activity along the trail had resumed. In 1880 a railroad reached Santa Fe, and use of the Santa Fe Trail declined.