Transferred in May 1916 to the destroyer, Conolly was aboard her when the United States entered World War I in April 1917. Smith performed escort duty in European waters out of Brest, France. Conolly was awarded the Navy Cross for his actions in connection with the salvaging of the transport ship, which was hit by two torpedoes launched by the German submarine in August 1918. Conolly, with a party of eight others remained on board the badly damaged ship for five days, steering by hand and handling the lines from the tugs, while the ship was towed to port.
Inter-war period
Conolly returned to the United States in November 1918, fitting out, and serving as Executive Officer of the destroyers, and in turn. From August 1920 he studied electrical engineering at Annapolis and Columbia University, New York, receiving a Master of Science degree in June 1922. He then served aboard the battleship, transferring to the battleship in March 1924 to serve as assistant Engineer Officer until September 1925. He then returned to Annapolis, this time as an instructor in the Department of Electrical Engineering and Physics. In June 1927 Conolly returned to sea as Engineer Officer of the light cruiser. In August 1929 he assumed command of the destroyer. He completed the junior course at the Naval War College, Newport, Rhode Island in May 1931, and remained on the staff for two years. In May 1933 Conolly reported as aide and Flag Secretary on the staff of Commander Cruisers, Scouting Force, and from April 1935 until June 1936 he served as Navigator aboard the battleship. He then returned to the Naval Academy, serving as an instructor in the Department of Electrical Engineering and Physics, and later in the Department of Seamanship and Navigation. Conolly assumed command of Destroyer Division 7 in May 1939, transferring to Destroyer Squadron 6 on 30 January 1941. He was at sea, in command of DESRON 6 at the time of the Japanese attack on Pearl Harbor on 7 December 1941.
World War II
Conolly participated in the initial attack on the Gilbert and Marshall Islands on 1 February 1942, as part of the force under the command of Admiral William Halsey, Jr., and in April his destroyers served as escort for the aircraft carrier, from which Lieutenant General Jimmy Doolittle's aircraft took off for the first bombing raid on Tokyo. He also participated in a shore bombardment of Wake Island in command of the destroyers in Rear Admiral Raymond A. Spruance's Task Group. Promoted to rear admiral in July 1942, Conolly served on the staff of the Chief of Naval Operations and Commander-in-Chief Fleet Admiral Ernest King. Between March and October 1943 Conolly served with the Amphibious Force Atlantic Fleet, taking part in the invasions of Sicily and Italy. Transferred to the Pacific, he was with amphibious forces in the Pacific and participated in the landings on Kwajalein, Wake and Marcus Islands. Conolly commanded Group 3, Amphibious Force, Pacific Fleet during 1944 and 1945, and led the landings on Guam in July 1944, and the Lingayen Gulf in January 1945. Conolly gained the nickname "Close-In Conolly" from his insistence that fire support ships should be extremely close to the beach during amphibious assaults. Conolly believed that strong fortifications could be neutralized only by direct hits, which could only be achieved from the shortest possible range.
