Convention led to a general meeting in Philadelphia the following May. Thus, George Washington's lobbying for interstate cooperation on the Potomac helped prepare the way for the Constitutional Convention of 1787. Building the canals Five skirting canals were made: Little Falls, Great Falls, Seneca Falls (across from Seneca Creek), Payne's Falls of the Shenendoah, and House Falls, (near Harpers Ferry, Virginia, now West Virginia). Three of the canals did not require locks: the Seneca Falls, House Falls, and Payne's Falls. Little Falls used wooden locks, which were not meant to be permanent. At Great Falls, the Potomac presented physical obstacles to travel as well. Narrow and winding in places, it drops over 600 feet in 200 miles from Cumberland to sea level. Spring rains swell the river to dangerous heights; summer droughts can render it impassable. To make the river navigable by even shallow draft boats, the Patowmack Company had to dredge portions of the riverbed and skirt five areas of falls. Little Falls Canal The Little Falls canal ran 3814 yards on the Maryland side of the river. The original locks, near today's Fletcher's Boat House, were made of wood, and the canal was finished in 1795. These wooden locks were replaced with stone locks in 1817, and had a lift of 37 feet. The first two locks were named "Martha" and "George" (after Martha Washington and George Washington). This canal was later repurposed for the Chesapeake and Ohio Canal (C&O), partially as Feeder #1, and as the canal itself from Lock 5 to just before Fletcher's Boat House. The remains of the stone locks were destroyed when the Baltimore and Ohio Railroad (B&O) built its Georgetown Branch line c. 1910. (The rail line was later abandoned and converted to the Capital Crescent Trail in the 1990s.) Great Falls Canal By far the most demanding task was building a canal with locks to bypass the Great Falls of the Potomac River. Roaring over the rocks, the river drops nearly 80 feet in less than a mile. Swift currents, solid rock, and constant financial and labor problems hindered progress on the Patowmack Canal at Great Falls. Construction begun in 1785 and took seventeen years to complete - six years longer than the time required to locate, build, and begin occupying a new federal city, Washington, D.C., ten miles downriver. Construction required engineering skills and a labor force not easily found