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. Duluth Ship Canal: The Duluth Ship Canal is an artificial channel cut through Minnesota Point, providing direct access to Duluth harbor from Lake Superior. Duluth Ship Canal:  Begun privately in 1871, it was put under federal supervision and maintenance several years later.
19th century