Ships
- USS Halsey Powell (DD-686) Captain, 25 October 1943 – 6 October 1944
William Thomas McGarry was born in Arkansas on 10 January 1905 and graduated from the United States Naval Academy with the class of 1927. He was promoted to lieutenant on 30 June 1936 and to lieutenant commander on 1 July 1941. On 1 September 1942, in the second year of the war, the Navy gave him the temporary rank of commander.
His first wartime command was the destroyer Jeffers (DD-621). He became her commanding officer on 5 November 1942, the day she went into commission, and stayed with her until 26 August 1943. That tour covered the new ship's fitting out and her opening months at sea before he was ordered to a destroyer still building in New York.
He placed Halsey Powell (DD-686) in commission on 25 October 1943 at the Bethlehem Steel yard on Staten Island. The Fletcher-class destroyer had been launched there on 30 June 1943, with the widow of Captain Halsey Powell, the World War I officer for whom she was named, as sponsor. McGarry took her through shakedown along the East Coast. On 13 December 1943 Halsey Powell, together with Marshall and Wadleigh, took over the escort of the battleship Iowa. On 20 January 1944 she sailed from Norfolk for the Pacific and reached Pearl Harbor on 12 February.
From Hawaii she ran out to Majuro and brought tankers back, then returned to the Marshalls in March for patrol and escort duty while American troops occupied the islands. On 23 March 1944 Halsey Powell delivered a series of depth-charge attacks on the Japanese submarine I-32. When her charges were used up, Manlove and PC-1135 pressed the hunt and sank the submarine.
McGarry kept Halsey Powell with the fast carriers for the rest of his cruise. In April 1944 she screened the force covering the Hollandia landings on New Guinea. In June she was off Saipan for the invasion of the Marianas and the Battle of the Philippine Sea. She stayed on that screen through the summer operations in the western Carolines and the early October strikes toward the Philippines. On 6 October 1944 he turned the ship over to Sidney Douglas Buxton Merrill. On 20 March 1945 the Navy advanced McGarry to the temporary rank of captain.