In the American Old West, trails were used by immigrants from the eastern United States, between 1830 and 1870. These colonists began to settle various regions of North America west of the Interior Plains, during the overland migrations of the mid-19th century. Settlers following these 'Westward ways' were spurred by various motives, among them including persecuted Mormons seeking freedom of religion. After the end of the Mexican-American War in 1849, there were many new enticing American conquests. Legislation like the Donation Land Claim Act and critical events like the California Gold Rush further incited colonists to travel overland west.
There were two major wagon networks, one based typically out of Missouri and the other out of Santa Fe de Nuevo México. Three of the Missouri-based routes were collectively known as the Emigrant Trails, the Oregon, Mormon, and California Trails. Historians have estimated at least 500,000 emigrants used these three trails from 1843–1869, and despite growing competition from transcontinental railroads, some use continued into the early twentieth-century. Three of the major southern routes were the Santa Fe Trail, the Southern Emigrant Trail, and the Old Spanish Trail and its wagon road successor the Mormon Road, a Southern Route of the California Trail used in the winter that used the western half of the Old Spanish pack horse trail. The trip was arduous, fraught with risks from infectious diseases, dehydration, injury, malnutrition, and harsh weather, with up to one-tenth dying along the way, usually due to disease.