In the history of the American frontier overland trails were built by pioneers throughout the 19th century and especially between 1829 and 1870 as an alternative to sea and railroad transport. These immigrants began to settle much of North America west of the Great Plains as part of the mass overland migrations of the mid-19th century. Settlers emigrating from the eastern United States were spurred by various motives, among them religious persecution and economic incentives, to move to destinations in the far west via routes including the Oregon Trail, California Trail, and Mormon Trail. After the end of the Mexican–American War in 1849, vast new American conquests again enticed mass immigration. Legislation like the Donation Land Claim Act and significant events like the California Gold R