An indigenous pathway used long by Native Americans for travel and trade became the Santa Fe Trail, which developed into an international commercial highway after Mexico gained independence from Spain in 1821. Stretching 900 miles from Franklin, Missouri, to Santa Fe, it connected Mexico with the United States and carried both American and Mexican traders seeking new markets and commercial opportunities. After the U.S.-Mexican War ended with the Treaty of Guadalupe Hidalgo in 1848, freighting increased largely because of the need to supply a new system of U.S. military southwestern forts. By 1880, the Atchison, Topeka, and Santa Fe Railroad had replaced the well-worn ruts of the trail. Today, wagon-wheel ruts, historic buildings, sites, and landmarks remain along the Santa Fe National Historic Trail, and federal, state, and local agencies, private citizens, and non-profit organizations work together to protect them. The trail's designation as a national historic trail in 1987 increased awareness and protection and created opportunities for visitors to experience its route and related sites through museums, visitor centers, and tour routes.