In its day, the famous Erie Canal was the world's longest canal and America's greatest engineering feat. It was the principal route for emigrants from the East and agricultural products from the West. Before construction of the canal, New York City was the nation's fifth largest seaport, behind Boston, Baltimore, Philadelphia and New Orleans. Within 15 years of its opening, New York was the busiest port in America, moving tonnages greater than Boston, Baltimore and New Orleans combined.
Locks

YearAdded:
Image Credit: Courtesy Flickr/Doug Kerr (CC BY-SA 2.0)Image Caption: Erie Canal - Waterford, NYEra_date_from: 1825
1967

The Dismal Swamp Canal was created as a 22-mile waterway, extending from Deep Creek, Virginia to South Mills, North Carolina. The canal enabled North Carolina producers of building and agricultural products to deliver goods to the Port of Norfolk where they were transferred to ocean-going vessels.
YearAdded:
Image Credit: Photo by Edwin S. Grosvenor (CC BY 2.0)Image Caption: Dismal Swamp CanalEra_date_from: 1805
1987