For almost 60 years, from 1821 to 1880, the Santa Fe Trail formed part of a complex web of international trade and business, beginning as a connection from the Missouri frontier in the United States to Santa Fe in Mexico and spanning 900 miles with links to cities deep in Mexico through El Camino Real de Tierra Adentro. In its early years, this trade stabilized and supported the economies of Missouri and the Mexican province of New Mexico during a time of monetary upheaval in both the U.S. and Mexico. Before 1821, Spain's colonial policy restricted the kind and number of trade goods available in New Mexico, but those barriers were lifted after Mexico achieved independence in 1821, allowing merchants such as Antonio Martinez, Juan Jose Delgado, Albert Speyer, and Charles Ilfeld to prosper. Trader William Becknell made his pioneering trip to Santa Fe in 1821 and returned in 1822 with wagons, earning the title "Father of the Santa Fe Trail." After the successful American invasion of the Southwest in 1846, the character of the trade changed as fewer individual traders participated and more commercial firms entered the trade, transforming the New Mexico economy from barter to cash. After 1865, the railroad moved westward from Missouri and reached New Mexico in 1880, replacing the trail with steam engines and beginning a new era of transportation.