Lewis Nixon was a naval architect, shipbuilding executive, public servant, and political activist. He designed the United States' first modern battleships, and supervised the construction of its first modern submarines, all before his 40th birthday. He was briefly the leader of Tammany Hall. He started an ill-fated effort to run seven major American shipyards under common ownership as the United States Shipbuilding Company, and he was the chair of the New York City commission that began construction of the Williamsburg Bridge.

A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as boats rather than ships irrespective of their size.