Potomac

an important river of the Chesapeake region. It forms the boundary between Maryland and the Virginias. The total length is about 400 miles. The chief branches are the Shenandoah from the south and the Monocacy from the north. The upper course of the river is much interrupted by rapids. At Harper's Ferry it has cut one of those famous passages known as a water gap. Between Harper's Ferry and the city of Washington there are numerous rapids and falls. The Great Fall, a cataract about thirty-five feet high, is situated a dozen miles or so above Washington. The river is navigable for sea-going vessels as far as Washington. It was at one time a river of commercial importance; the early settlers of Virginia and Maryland packed their tobacco in hogsheads, rolled them down woodland roads to the Potomac or its branches, and shipped them to England. The upper valley was one of the earliest thoroughfares to the interior. The Chesapeake and Ohio Canal was built along its banks. The river is rich in historical associations. Its broad expanse was the delight of George Washington. See Mount Vernon; Arlington; Washington, etc.