In the 18th-century migrations, few trails in America were more important than the Indian route which ran east of the Appalachians from Pennsylvania to Georgia. This Ancient Warriors Path had long been used by Iroquois tribesmen of the north to travel south and trade or make war in Virginia and the Carolinas. By a series of treaties with the powerful Five Nations of the Iroquois, the English acquired use of the Warriors Path. After 1744 they took over the land itself. The growth of the route into the principal highway of the colonial backcountry was important in the development of the nation. Over this road came English, Scots-Irish, and German settlers to claim land. The Warriors Path led from the Iroquois Confederacy around the Great Lakes through what later became Lancaster County, Pennsylvania, to Bethlehem, York, and Gettysburg, into western Maryland around what is now Hagerstown, across the Potomac River at Evan Watkins Ferry, following the narrow path across the "back country" (or "up country" or "Piedmont") to Winchester, Virginia, through the Shenandoah Valley, to Harrisburg, Staunton, Lexington, and Roanoke, to Salem, North Carolina, to Salisbury, where it was joined by the east–west Catawba and Cherokee Trading Path at the Trading Ford across the Yadkin River in Rowan County, to Charlotte, then to Rock Hill, South Carolina, where it branches into two routes to Augusta and Savannah, Georgia.
(Source: The Scots-Irish From Ulster and The Great Philadelphia Wagon Road, by Brenda E. McPherson Compton, http://www.electricscotland.com/history/america/wagon_road.htm)