USS South Dakota (BB-57) was a battleship in the United States Navy from 1942 until 1947. The lead ship of her class, South Dakota was the third ship of the US Navy to be named in honor of the 40th state. The four ships of the class are considered to be the most efficient battleships designed under the limitations of the Washington Naval Treaty. During World War II, the battleship first served a tour in the Pacific theater, where it fought in two battles in 1942 that earned the ship and its crew a Navy Unit Commendation before returning to New York in December 1942 for an overhaul and battle repairs.