The Harvey C. Barnum, Jr. (DDG 124) is the 74th Arleigh Burke-class guided-missile destroyer and the first ship in the United States Navy named in honor of retired Marine Corps Col. Harvey C. Barnum, Jr., who received the Medal of Honor for heroism displayed during an action outside Ky Phu, Quang Tin Province, Vietnam, in December 1965.

May 21, 2021 The keel authentication ceremony for the future USS Harvey C. Barnum, Jr., was held at the Bath Iron Works shipyard.

July 29, 2023 The Pre-Commissioning Unit (PCU) Harvey C. Barnum, Jr., was christened during a 10.30 a.m. EDT ceremony at Bath Iron Works in Bath, Maine. Ms. Martha Hill, the wife of the ship's namesake, served as the sponsor.

October ?, The Harvey C. Barnum, Jr., was launched for the first time from a floating dry-dock and moored pierside on Bath Iron Works shipyard.

July 17, 2025 PCU Harvey C. Barnum, Jr., moored at Pier 3 on Bath Iron Works shipyard after a two-day underway for Builder's (Alpha) trials; Underway again from Aug. 11-14; Underway for acceptance trials on Sept. 17; Moored at Ocean Gateway Pier II in Portland, Maine, for an overnight stop on Sept. 18; Returned to Bath on Sept. 19.

November 17,  U.S. Navy officially accepted delivery of the future USS Harvey C. Barnum, Jr., during a brief ceremony aboard the ship.

March 4, 2026 PCU Harvey C. Barnum, Jr., commanded by Cmdr. Benjamin R. Cantu, departed Bath, Maine, for the last time en route to Norfolk, Virginia; Moored at Pier 2N on Naval Station Newport, R.I., from March 5-10.

March 13, PCU Harvey C. Barnum, Jr., moored at Berth 7, Black Falcon Cruise Terminal in South Boston, Mass., for a five-day port visit in conjunction with the St. Patrick’s Day.

March 20, The Harvey C. Barnum, Jr., moored at Berth 6, Pier 5 in its homeport of Naval Station Norfolk for the first time; Underway for routine training, in the Virginia Capes Op. Area, on March 30; Anchored at Explosives Anchorage G4 for a brief stop before moored at Berth 4, Pier 14 on April 3; Moved to Berth 3, Pier 14 on April 7.

April 11, USS Harvey C. Barnum, Jr., was commissioned during a 10 a.m. EDT ceremony at Pier 14 on Naval Station Norfolk.

April 13, The Barnum moved from Pier 14 to Berth 1, Pier 6 on Naval Station Norfolk; Underway in the Virginia Capes Op. Area from April 20-24 and April 27-30.

May 8, USS Harvey C. Barnum, Jr., moored at Berth 3, Pier 14 on Naval Station Norfolk after a one-day underway off the coast of Virginia; Moved to Berth 6, Pier 7 on May 14.