LST-31 was laid down on 2 February 1943 at Pittsburgh, Pa., by the Dravo Corp.; launched on 5 June 1943; sponsored by Mrs. Maurice Endres; and commissioned on 21 July 1943.
During World War II, LST-31 served in the Asiatic-Pacific theater and took part in the following operations :
Gilbert Islands operation—November and December 1943
Marshall Islands operation:
(a) Occupation of Kwajalein and Majuro Atolls—January and February 1944
(b) Occupation of Eniwetok Atoll—Februaryand March 1944
(a).Capture and occupation of Saipan—June through August 1944
Tinian capture and occupation—July and August 1944
Okinawa Gunto operation:
(a) Assault and occupation of Okinawa Gunto—May 1945
Immediately following the war, LST-31 performed occupation duty in the Far East until early January 1946. She returned to the United States and was decommissioned on 8 January 1946. On 1 July 1955, LST-31 was named Addison County after a county in Vermont. Her name was struck from the Navy list on 11 August 1955, and she was sunk as a target.
Addison County earned five battle stars for World War II service as LST-31.