The Navy Yard was an important United States naval shipyard for almost two centuries. The shipyard's greatest period came during World War II, when the yard employed 40,000 people who built 53 ships and repaired 574. During this period, the yard built the famed battleship New Jersey and its 45,000-ton sister ship, Wisconsin. Today the shipyard has undergone major redevelopment, and is now a large campus that employs nearly 15,000 people across a mix of industries. A visit to the Navy Yard includes the opportunity to view public art, modern parks, historic buildings, and a "mothball" fleet of ships.