Popular literature and frontier studies stress that Americans moved west to farm or to seek a new beginning. Scott Rohrer argues that Protestant migrants in early America relocated in search of salvation, Christian community, reform, or all three.

In Wandering Souls, Rohrer examines the migration patterns of eight religious groups and finds that Protestant migrations consisted of two basic types. The most common type involved migrations motivated by religion, economics, and family, in which Puritans, Methodists, Moravians, and others headed to the frontier as individuals in search of religious and social fulfillment. The other type involved groups wanting to escape persecution (such as the Mormons) or to establish communities where they could practice their faith in peace (such as the Inspirationists). Rohrer concludes that the two migration types shared certain traits, despite the great variety of religious beliefs and experiences, and that "secular" values infused the behavior of nearly all Protestant migrants.

Religion's role in transatlantic migrations is well known, but its importance to the famed mobility of Americans is far less understood. Wandering Souls demonstrates that Protestantism greatly influenced internal migration and the social and economic development of early America.