After flight instruction at Miami and Jacksonville, Florida, he was appointed naval aviator on 26 August 1941 and received a reserve ensign's commission on 18 September.

The ship was laid down on 9 September 1943 at Port Newark, New Jersey, by the Federal Shipbuilding & Drydock Co.; launched on 28 November 1943; sponsored by Mrs. Margaret Baker, the mother of Ens.

Upon her return to New York on 24 March, the ship underwent a week long overhaul before carrying out antisubmarine warfare (ASW) training at Casco Bay, Maine.

Each managed to limp into port for repairs, although their assailant, U-616, soon fell victim to the combined efforts of eight American destroyers and several British aircraft.

On 2 July, its air patrol sighted a surfaced U-boat, but her lookouts must have spotted the planes because a search by two escorts dispatched proved to be fruitless.

While hunting south of Newfoundland on 5 July, Baker picked up a submarine on her sound gear at 1907, and carried out a depth charge attack.

Nearby, Thomas (DE-102), the division flagship, observed that Baker's depth charge attacks and gunnery had been effective because smoke and flame issued from the conning tower.

After voyage repairs at the Navy Yard Annex, Bayonne, New Jersey, from 25 August to 7 September, the destroyer escort honed her ASW skills at Casco Bay before proceeding to Hampton Roads along with the rest of CortDiv 48.

After returning to New York on New Year's Eve, Baker operated out of Newport, Rhode Island, from 4 to 21 January 1945, serving as plane guard for escort carrier Prince William (CVE-31) as she conducted pilot qualifications.

Baker sustained heavy, but not critical, damage: sprung frames, ruptured steam lines, downed lifelines, shorted out fire control circuits, and inoperable sound gear.

After the end of the war with Germany, Baker operated out of Quonset Point, Rhode Island, as plane guard for escort carriers Card and Croatan (CVE-25) as they qualified pilots, carrying out that duty through September.

She participated in the big Navy Day observances at New York City on 27 October; anchored in the Hudson River above the George Washington Bridge, she fired a 21 gun salute to President Harry S. Truman, who was embarked in Renshaw (DD-499) to review the assembled fleet.

Going into the New York Naval Shipyard the next day for repairs, Baker cleared the yard for Quonset Point on the 31st, to resume her plane guard occupation, but soon received orders re-routing her to New London, Connecticut.

Over the next few weeks, Baker and U-977 visited Albany, Poughkeepsie, and Newburgh, New York; Wilmington and Lewes, Delaware; Richmond, Virginia; and Washington, D.C., affording the American public in those places an opportunity to see a German U-boat and a destroyer escort to stimulate interest in the Victory Loan fund raising drive, winding up the tour at the nation's capital on 8 December 1945.