The "North Carolina" class was the first new battleship design built under the Washington Naval Treaty system; her design was bound by the terms of the Second London Naval Treaty of 1936, which added a restriction on her main battery of guns that they be no larger than . The General Board evaluated a number of designs ranging from traditional battleships akin to the "standard" series or fast battleships, and ultimately a fast battleship armed with twelve 14-inch guns was selected. After the ships were authorized, however, the United States invoked the escalator clause in the treaty that permitted an increase to guns in the event that any member nation refused to sign the treaty, which Japan refused to do.