The Chesapeake and Ohio (C&O) Canal is one of the most intact and impressive survivals of the American canal-building era. The C&O Canal is unique in that it remains virtually unbroken and without substantial modification affecting its original character for its entire length of 185 miles. The C&O Company was chartered in 1825 to construct a shipping canal connecting tidewater on the Potomac River in DC with the headwaters of the Ohio River in western Pennsylvania, thereby providing an economical trade route between the eastern seaboard and the trans-Allegheny West. The company acquired the rights of the Potomac Company, formed by George Washington and associates to improve navigation on the Potomac. That venture had attempted to achieve its objective by deepening the channel and cutting skirting canals around impassible rapids, but the flow of the river proved too erratic to make these measures successful. This experience led C&O promoters to adopt plans for a separate canal paralleling the river. President John Quincy Adams turned the first spadeful of earth in ceremonies at Little Falls, Maryland, on July 4, 1828. On the same day, construction of the Baltimore and Ohio Railroad westward from Baltimore was begun-a move that would have significant implications for the ultimate fate of the canal and the canal era generally.