She was laid down on 28 August 1943, by Consolidated Steel Corporation in Los Angeles, California, launched on 27 September 1943, sponsored by Mrs. Harry L. Crotzer, and commissioned on 6 March 1944.

Rockford then returned to New Guinea, remaining there until 15 October 1944, when she began a voyage to the United States West Coast via Manus Island and Pearl Harbor, Territory of Hawaii.

On 13 November 1944, during the final leg of the voyage, Rockford and the minesweeper USS Ardent (AM-340) attacked and sank the Japanese submarine I-12 midway between Hawaii and California; there were no survivors from I-12.

[5] In February 1946, the United States began negotiations for the return of ships loaned to the Soviet Union for use during World War II.

[6] Reverting to her original name, Rockford lay idle in the Pacific Reserve Fleet at Yokosuka until the United States loaned her to the Republic of Korea on 23 October 1950 for Korean War service in enforcing the United Nations blockade against North Korea and harassing enemy forces.