He assumed command of Ingraham 19 July 1941 and with the outbreak of World War II commenced escort duty for convoys sailing from New York and Halifax to the British Isles.

After shakedown in the Caribbean, Haynsworth departed New York on 20 September 1944 escorting Queen Mary with Prime Minister Winston Churchill on board.

Rendezvousing with British escorts, she returned to New York and sailed on 26 September via the Panama Canal Zone and San Pedro, arriving Pearl Harbor on 20 October.

Haynsworth sailed on 16 December for Ulithi and joined Vice Admiral John McCain's Fast Carrier Task Force 38 for the final assaults on the Japanese.

Their primary mission was to conduct air strikes against strategic Japanese positions along the China coast, and Formosa, and to harass enemy shipping during the landings at Luzon on 9 January 1945.

During the afternoon, three Japanese picket boats that had evaded detection in thick fog were spotted by Haynsworth and promptly sunk, taking 12 prisoners.

In addition to damaging aircraft frame and engine plants, a number of ships and small craft were attacked and sunk in Tokyo Bay, the biggest prize being the 10,600-ton Yamashiro Maru.

Landings were made on the Japanese fortress 1 April, with Task Force 58 providing support, and Haynsworth frequently aiding in the destruction of enemy aircraft during the many attacks, where "the fleet had come to stay."

Returning to active service in March 1947, Haynsworth based her operations from Algiers, Louisiana, conducting reserve training cruises in the Gulf and in the Caribbean until the summer of 1949.

Between 1956 and 1960, she made five deployments to the Mediterranean, supporting the Navy's peacekeeping role and keeping a watchful eye on the troubled spots of the free world.

Late in 1961, while in the Mediterranean, Haynsworth delivered emergency food rations to flood-ravaged Africa, and on 3 October 1962, she stood by off Cape Canaveral as a rescue ship and witnessed the take off of astronaut Comdr.

After being assigned to Reserve Destroyer Squadron 34, Haynsworth operated out of Galveston while providing valuable on board training facilities for hundreds of Naval Reservists.