The town is located at the eastern edge of the North Carolina Piedmont, on the Roanoke River at the fall line, which marks the area where an upland region (continental bedrock) and a coastal plain (coastal alluvia) meet. The fall line is typically prominent where a river crosses it, for there will usually be rapids or waterfalls. Because of these features, river boats typically could not travel any further inland. Because settlements needed a port and a ready supply of water power, they often developed where the river crosses the fall line. The Roanoke River and its falls inspired the development of Roanoke Rapids; businessmen such as Sam Patterson and other textile manufacturers used the river to power their mills.