In the three decades before the Civil War, Americans had built a vast railroad system across the eastern United States. By the 1860s, the iron fingers of the rail system reached into the edge of the frontier, from Wisconsin to Texas. With the riches of gold and silver to be found in the far West, Americans were anxious to expand the rails westward.

The railroad train was also the perfect instrument for those who believed in Manifest Destiny. As Senator Thomas Hart Benton put it when proposing a cross-country rail system:

Emigrants would flock upon [the railroad] like pigeons to their roosts, tear open the bosom of the virgin soil, and spring into existence the long line of farms and houses, of towns and villages, of orchards, fields, and gardens, of churches and schoolhouses, of noisy shops, clattering mills, and thundering forges, and all...