What century were the Leiper Canal and Duluth Ship Canal built?
Leiper Canal Early in the 19th century, the Leiper Canal built in 1828-29 during the middle of the American canal age ran about 3 mi along Crum Creek in Delaware County to its mouth in Eastern Pennsylvania's Delaware Valley carrying its owners quarried products to docks on the Delaware River tidewater until 1852.
Round Island Channel The Round Island Channel is a navigable Lake Huron waterway located between Mackinac Island and Round Island in the Straits of Mackinac. It forms a key link in the lake freighter route between Lake Superior and Lake Michigan, on which millions of tons of taconite iron ore are shipped annually. The channel also provides access to the harbor of Mackinac Island, Michigan, and is used by commercial ferryboats delivering passengers to the small island city.