As the Allies slowly gained the upper hand in the Battle of the Atlantic, newer and more modern destroyers replaced the aging flush-deckers as front line convoy escorts. Throughout 1944, "Upshur" operated between Norfolk, Virginia, and Quonset Point, Rhode Island, serving as plane guard and target vessel during qualification trials for aircraft carriers. During this period, she worked successively with , , , , , , , and . Reclassified as a miscellaneous auxiliary, AG-103 on 3 June 1945, "Upshur" was plane-guarding for when Japan capitulated on 15 August, ending the war in the Pacific. Decommissioned at Norfolk, Virginia, on 2 November 1945, "Upshur" was struck from the Navy list on 11 November; was sold to the Northern Metals Company of Philadelphia on 26 September 1947; and was scrapped by April 1948.