Following a shakedown cruise in the Caribbean Sea, Woolsey joined the Atlantic Fleet at the beginning of the second week in September. Initially, she served on the Neutrality Patrol, established by President Franklin D. Roosevelt to keep the war in Europe from spreading to the western hemisphere. For a time, she also served as a unit in the screen of the newly commissioned battleship North Carolina (BB 55). As the year 1941 waned and the United States approached closer and closer to active belligerency, Woolsey began escorting convoys between the United States and Iceland.
The attack on Pearl Harbor and America’s entry into World War II found the destroyer in Iceland completing the first leg of one such round-trip voyage. War brought a change to Woolsey’s range of duties. Her convoy escort work was broadened to include voyages to the British Isles and Puerto Rico. That duty occupied her energies until the fall of 1942 when she participated in her first invasion operation.
For Operation “Torch,” the invasion of Vichy French-controlled North Africa, Woolsey was assigned to Destroyer Squadron (DesRon) 13 which served as antisubmarine screen for the Center Attack Group, the Fedhala landing force. That task organization sortied from Hampton Roads, Virginia on 24 October and, four days later, rendezvoused with the other units that comprised Task Force (TF) 34. After a meandering and mercifully uneventful crossing, the ships reached the vicinity of the Moroccan coast and each of the three task groups went their separate ways. Woolsey arrived off Fedhala with the Center Attack Force just before midnight on 7 November. Between 0500 and 0600 the next morning, the troops landed at Fedhala and consolidated their beachhead quickly. Resistance soon dissipated, and Woolsey seems not to have participated actively in this phase of the operation other than to conduct antisubmarine patrols against a menace which, at that juncture, failed to materialize.
Later, however, the German Navy belatedly took a hand in the fracas. U-boats began attacking the transports. On the 11th, U-173 sank Joseph Hewes (AP 50). Between then and the 15th, several other attacks occurred. On the 16th, U-173 returned to the area and probably was the German submarine responsible for torpedoing Electro (AK 21). That time though, the U-boat failed to make good her escape. Woolsey, still on antisubmarine patrol, caught the submarine’s reflection with her sonar and, joined by Swanson (DD 443) and Quick (DD 490), charged to the attack. The three destroyers made a coordinated depth charge assault that sent U-173 to oblivion. The following day, Woolsey departed the Moroccan coast to return to Hampton Roads, where she arrived on the 30th.
After a series of training operations along the eastern seaboard—primarily off the New England coast— Woolsey began duty escorting transatlantic convoys in mid-January 1943. On the 14th, she departed New York with Convoy UGF-4. The convoy reached Casablanca on the 25th and, after a week in port, Woolsey escorted the return convoy, GUF-4, back to New York, arriving there on 13 February. At the beginning of March, she helped shepherd Convoy UGF-6 to Casablanca. She then made a brief round-trip voyage from Casablanca to Gibraltar and back before returning to the East Coast with GUF-6 early in April. Woolsey then plied the waters of the eastern seaboard until mid-May, conducting antisubmarine patrols and screening coastwise convoys between Norfolk and New York.
On 14 May, Woolsey put to sea from New York with her last transatlantic convoy, UGS-8. She and her charges reached Casablanca on 1 June and the destroyer remained there a fortnight. On the 15th, she departed Morocco but, instead of returning to the United States as she had done in the past, she headed via Gibraltar to Algiers on the Mediterranean coast of North Africa.
When Woolsey reached Gibraltar the next day, an Atlantic phase of her wartime career ended and the Mediterranean phase began. She reported for duty with the Eighth Fleet just in time to participate in the invasion of Sicily. Operations in Italian waters consumed the bulk of her time and energy during the ensuing eight months. For the Sicily assault, she drew duty as a fire support ship for one of three sectors into which the Licata landing beaches were divided. Save for one brief round-trip voyage to Algiers in mid-July, Woolsey provided gunfire support for the Army operating ashore on Sicily and helped to defend Allied shipping from German air attacks. Though she appears not to have accounted for any Luftwaffe aircraft, she did succeed in destroying an enemy railroad battery with gunfire.
By mid-August, with Sicily secured, Woolsey began preparations for the landings on the Italian mainland at Salerno. For that invasion, she was assigned to the Southern Attack Force fire support group which consisted of five cruisers—four American and one British—and the four destroyers of Woolsey’s DesDiv 25. In that capacity, she supported the landings on the southern sector of the Gulf of Salerno shoreline. During the assault on 9 September, however, she received only one call for fire support. That event occurred just after 1630 when her shore fire-control party called upon her to join Bristol (DD 453) in shooting up an enemy tank formation.
After completing her mission at Salerno the next day, Woolsey returned to more routine missions. She made voyages between Naples and North African ports escorting supply echelons to the expanding Italian campaign. While operating outside of Oran, Algeria, on 16 December, she encountered the German submarine U-73. After forcing the U-boat to surface with a full pattern of depth charges, Woolsey’s gunners went to work and completed the destruction of U-73. The destroyer rescued and made prisoners of the U-boat’s 23 survivors.
Late in January 1944, Woolsey returned to amphibious operations, this time as a unit of the Fire Support Group for the Anzio landings. Arriving off the beachhead on 22 January 1944, she delivered call fire support for the troops as they landed. The relative ease experienced during the opening phase at Anzio, however, belied the actual complexion of the campaign. Failing to break out of the beachhead early, the Army forces were soon surrounded on three sides by German forces which threatened to push them into the sea. The dogged determination of American infantrymen and the yeoman-like support provided them by the Navy enabled the troops ashore to hold on until a link-up was made with the Salerno forces in May. During the first month of that desperate struggle, Woolsey provided gunfire support for the troops ashore and protected the ships which constituted their lifeline to the outside world. Late in February, however, she departed the Italian campaign to return to the United States for necessary repairs. After a stop at Gibraltar on 17 February, she headed via Horta in the Azores to Boston, Massachusetts, where she arrived on the 25th.
Completing her repairs at Boston in mid-March, she conducted refresher training at Casco Bay, Maine, before heading back to the Mediterranean at the end of the third week in April. She stopped at Gibraltar on the last day of that month and arrived at Oran on May Day. The ensuing three months saw her operating out of Oran conducting antisubmarine patrols of the approaches to that port. While operating with a hunting group composed of Benson (DD 421), Ludlow (DD 438) and Niblack (DD 424) in mid-May, Woolsey experienced her third and last encounter with a German U-boat. A report of torpedo tracks from a newcomer to the Mediterranean, U-960, brought DesDiv 25 to the area between Oran and Cartagena early on the 17th to commence a two-day search and destroy mission. During the night of 18 and 19 May, the four destroyers split themselves into two search groups and began searching a possible submarine track 10 miles to each side of it. About an hour and 40 minutes into the midwatch, the four warships received word that a plane had spotted the submarine some 10 miles ahead of Niblack and Ludlow. Those two ships charged to the attack and, by the time Woolsey arrived on the scene with Benson and Madison (DD 425), the two destroyers had succeeded in forcing the U-boat to surface after delivering 11 depth charge attacks over the space of four hours. Immediately, all five destroyers opened fire on the submarine while a British Wellington bomber shifted through the melee at low altitude to drop depth bombs near U-960. The German ship suffered a number of 5-inch hits before submerging again. Niblack responded with more depth charges. That attack evidently rung the death knell for U-960, for she immediately resurfaced, and her crew scrambled off just as she made her final plunge at about 0715 on the 19th. The destroyers picked up the U-boat’s captain and 21 of her crew. While Niblack and Ludlow received official credit for sinking the enemy submarine—no doubt a fair assessment considering their four-hour attack and the fact that Niblack probably delivered the coup de grace—Woolsey’s 5-inch gunfire probably contributed significantly to the enemy’s destruction.
Following that action, Woolsey continued relatively routine patrols until the end of July, when she began preparations for the invasion of southern France. For that operation, Woolsey was assigned to the Bombardment Group attached to “Camel” Force. In that capacity, she supported the landings on the right flank of the assault area—near St. Raphaël. During the 15 August invasion, her guns knocked out two German tanks but, although the Camel area assault proved to be the most heavily contested thrust, the entire southern France operation constituted little more than a walkover.
Consequently, very soon after the initial invasion, Woolsey shifted to supporting the 1st Airborne Division’s drive along the coast toward Italy. She fired upon enemy lines of communication along the coast—particularly roads—and supported the liberation of Cannes on 24 August. The destroyer continued her operations along the Franco-Italian coast until late October. At that time, she headed for Naples for a visit before returning to Oran, where she arrived on 29 November. The warship was back off the southern coast of France in mid-December and resumed her interdiction duties until mid-January 1945. At that time, she bade farewell to the Mediterranean and the Eighth Fleet. Following a brief tour of duty patrolling in the Azores, Woolsey returned to the United States, arriving in New York on 23 February.
After operating along the New England coast until late April and escorting a convoy to Great Britain in May, the warship returned home to receive a reinforced antiaircraft battery preparatory to her impending transfer to the war in the Pacific. Late in June, she steamed south to conduct refresher training out of Guantánamo Bay, Cuba. Completing that duty on 7 July, she transited the Panama Canal two days later and reported for duty with the Pacific Fleet. She stopped at San Diego, California from 18 July to 3 August. A week later, while she was still at Pearl Harbor, Japan capitulated. Late in August, she escorted a convoy carrying occupation troops to Japan. She stopped at Sasebo until 26 September and then began a voyage during which she made a series of port visits—at Manila, Shanghai, Okinawa and Saipan.
From the last-named place, Woolsey got under way on 3 November to return home. After stops at Pearl Harbor and San Diego, the destroyer ended her brief interlude with the Pacific Fleet on 29 November, when she retransited the Panama Canal. She arrived in Charleston, South Carolina on 4 December and began preparations for inactivation. On 8 March 1946, the destroyer was placed in commission, in reserve. Eleven months later, on 6 February 1947, she was placed out of commission. Berthed with the Charleston Group, Atlantic Reserve Fleet, for 10 years, Woolsey was towed to Boston in late October of 1957. Her name was struck from the Navy list on 1 July 1971, and she was sold to Andy International, Inc., for scrapping on 29 May 1974.