During World War II, the Wisconsin-based Manitowoc Shipbuilding Company constructed twenty-eight Gato Class fleet submarines, known as “Freshwater Submarines,” to bolster production at existing naval shipyards. After completion, the submarines traveled from Lake Michigan down the Illinois River, each passing this spot. Because some river channels were only seven feet deep, the boats were carried in a special floating dry dock, with their masts removed to clear bridges. Upon reaching New Orleans, the Manitowoc submarines were commissioned into the Silent Service. Four of these submarines—Golet, Kete, Lagarto, and Robalo—were lost during the war, along with 336 officers and enlisted men.