As the population in the New River valley increased in the 18th century, the western branch of the Great Wagon Road from Philadelphia to the backcountry of the Carolinas and Georgia crossed the region. The branch became known as the Wilderness Road. After Daniel Boone and others improved it about 1775, it was the main route of migration to Kentucky and the West through Cumberland Gap. This segment of the Wilderness Road ascended the Allegheny Mountains at Christiansburg, crossed the New River at Ingles Ferry, then continued west. In the 19th century, the Ingles Ferry Road was incorporated into the South Western Turnpike.