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.