On this day in Duluth in 1915, officials considered laying explosive mines in the Duluth-Superior harbor as defense against hostile attacks. The United States was facing increased pressure to join the European allies in their fight against Germany, and politicians were beating the war drums throughout the country. Communities were preparing themselves, and as the world’s largest inland port, the Duluth-Superior harbor was seen as a strategic target. There had already been talk of replacing the Duluth Naval Militia’s training ship, the USS Gopher, with a much larger, more battle-ready vessel, the Topeka, which had seen action in the Spanish-American War. The Duluth Naval Militia’s leader, Captain Guy Eaton, was joined by Lt. F. J. Wille and Chief Yeoman Leo Ketterer of the Minneapolis naval recruiting station in a tour of the harbor, plotting ways to defend it against enemy attack. Letterer told local newspapers that “Among the things we investigate was capacity of the Duluth-Superior harbor for the placing of mines, its landmarks for use of navigating ships in case lighthouses were abandoned in time of war, the accommodations of its hospitals, the extent of its food supply in a stringency and the medical corps available.” The harbor was never mined, and the Gopher was sent to Chicago to train sailors at the Great Lakes Naval Station. She was placed out of commission in 1923.