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.
Lock and Dam No. 2 Lock and Dam No. 2 is located along the Upper Mississippi River near Hastings, Minnesota and was originally built in 1907. The eastern dam portion is 722 ft wide and has 19 tainter gates. A hydroelectric station that produces about 4.4 megawatts is owned by the city of Hastings, while the 110 × lock is operated by the St. Paul district of the U.S. Army Corps of Engineers' Mississippi Valley Division. There's also a wide earthen dam on the western side of the facility.