Between 1821 and 1880, the Santa Fe Trail was primarily a commercial highway connecting Missouri and Santa Fe, New Mexico. In 1846, the Mexican-American War began and the Army of the West followed the Santa Fe Trail to invade New Mexico.
When the Treaty of Guadalupe ended the war in 1848, the Santa Fe Trail became a national road connecting the United States to the new southwest territories. The trail was also used by stagecoach lines, thousands of gold seekers heading to the California and Colorado gold fields, adventurers, fur trappers, and emigrants. In 1880 the railroad reached Santa Fe and the trail faded into history.
The National Park Service administers the Santa Fe National Historic Trail in partnership with other federal, state, and local agencies; non-profit organizations; and private landowners. The Santa Fe Trail Association, a partner of the National Park Service, is a national organization dedicated to preserving resources, and fostering public awareness and appreciation of the Santa Fe National Historic Trail.