Question: Which waterway, Chain of Rocks Lock or Dismal Swamp Canal, is the oldest continually operating man-made canal in the United States?

 It is the oldest continually operating man-made canal in the United States, opened in 1805, and closed in October 2016. The Dismal Swamp Canal is located along the eastern edge of the Great Dismal Swamp in Virginia and North Carolina in the United States.  It is part of the Intracoastal Waterway, an inland route, which parallels the east coast and offers boaters shelter from the Atlantic Ocean from Manasquan Inlet, New Jersey, to Brownsville, Texas.  The route runs through bays, lakes, rivers, streams, and canals, and includes the Intracoastal Waterway running from Norfolk, Virginia, to the Florida Keys. <SEP> Indian Creek is a partly natural and partly man-made waterway in the city of Miami Beach, Florida, United States.  It starts as a man-made canal where Biscayne Bay meets Lincoln Road, and runs along Dade Boulevard, forming the boundary between South Beach and the rest of the city.  At 24th street the canal opens into the natural waterway and continues north through the city past Allison Island where it opens into Biscayne Bay, till 71st Street where it merges with Normandy and Tatum Waterways and is no longer called Indian Creek. <SEP> Bridgeton Township is a township in Bucks County, Pennsylvania, United States.  The population was 1,277 at the 2010 census.  The township was originally a part of adjacent Nockamixon Township, but a division was arranged and signed on 1890.  This accord split an area of Nockamixon which ran west from the banks of the Delaware River to about one third the breadth of the original township.  This smaller area was unsurprisingly named "Bridgeton", as it was the site of wooden truss bridge which connected the towns of Upper Black Eddy and Milford, New Jersey.  The township originally contained several tiny hamlets, such as the aforementioned Upper Black Eddy, Narrowsville, and Ruppsville.  Upper Black's Eddy, as it was originally called, and Raubsville were named for notable landholders, while Narrowsville was named for a particularly thin portion of the Delaware River.  With the construction of a centralized post office in Upper Black Eddy, the usage of separate names for the smaller towns ceased in an official capacity, and the everyday errands of residents became centered on the largest of the towns.  What little commercial trade exists in the township is now centered solely in Upper Black Eddy, with any evidence of there being any distinctive, smaller villages existing only on outdated road-signs and maps.  Ringing Rocks Park is located within the township, as well as state game hunting lands.  Bridgeton Township is also home to the Homestead General Store, the oldest continually operating general store on the Delaware Canal. <SEP>  Its associated dam is just downstream of the Chain of Rocks Bridge, and the lock is located over 3 mi southeast on the Chain of Rocks canal.  The canal and locks allow river traffic to bypass a portion of the river that is unnavigable in low water due to an anticlinal exposure of bedrock in the river—a "chain of rocks". Chain of Rocks Lock, also known as Locks No. 27, is a lock situated at the southern end of Chouteau Island near St. Louis, Missouri on the Upper Mississippi River.