In early 1942, after the Japanese attack on Pearl Harbor, Mississippi rejoined the Pacific Fleet. She spent most of 1942 along the U.S. west coast and went to the South Pacific late in that year. In 1943, she took part operations against Kiska Island, in the Aleutians, and in the capture of the Gilbert Islands. During the latter operation, on 29 November 1943, Mississippi experienced another turret explosion, which took 43 lives. Following repairs, she participated in the capture of Kwajalein in February 1944 and bombarded Japanese-held islands in February and March. Later in the year, she was part of the force that invaded Peleliu and Leyte and defeated a Japanese task force in the Battle of Surigao Strait. Mississippi provided gunfire support for the Lingayen landings in January 1945 and for the conquest of Okinawa in March-June. The battleship was damaged by suicide planes in both operations. She was present in Tokyo Bay on 2 September 1945, when Japan formally surrendered and returned to the United States soon thereafter.
Mississippi was converted to a gunnery training and weapons development ship in 1946, and given the new hull number AG-128. In this role, she carried a variety of old and new guns and radars, while serving with the Operational Development Force in the Atlantic. During the mid-1950s, she was test ship for the Navy's first surface-to-air guided missile, the "Terrier". Decommissioned in September 1956, USS Mississippi was sold for scrapping in November of that year, after almost forty years of service.
I'll let the pictures speak for her.