During the first year and more after America entered the war against the Axis, the United States Navy suffered from an acute shortage of warships, particularly of antisubmarine warfare and escort types. To fill that need, an extensive ship construction and acquisition program was inaugurated. Part of that program consisted of placing orders with British and Canadian firms already tooled up to produce . Vitality (PG-100) was such a ship. However, before she was launched on 15 April 1943 by the Midland Shipyard in Canada, she was traded to the Royal Navy under the terms of the lend-lease agreement for a similar ship being constructed in Canada. The British renamed her HMS Willowherb, and she served in the Royal Navy for the duration of the war. On 11 June 1946, she was returned to the custod