Swasey was assigned to the Pacific Fleet and, after completing fitting out and sailing to the west coast, arrived at Pearl Harbor in the fall of 1919.

She served there until the summer of 1922, when she returned to San Diego, California.

Swasey was decommissioned at San Diego on 10 June 1922 and assigned to the reserve fleet for the next 17 years.

Swasey was reactivated on 18 December 1939 and – after an overhaul and sea trials – transferred to Britain on 26 November 1940 under the Destroyers for Bases Agreement.

Rockingham was modified for trade convoy escort service by removal of three of the original 4 in (102 mm)/50 cals and three of the triple torpedo tube mounts to reduce topside weight for additional depth charge stowage and installation of hedgehog.