The United States Maritime Commission built 671 large oceangoing vessels intended as convoy escorts in World War II. These were designated “destroyer escorts” and “frigates.” As indicated below, during the war the Americans transferred a total of ninety-nine of these vessels to Great Britain’s Royal Navy (seventy-eight destroyer escorts and twenty-one frigates); six destroyer escorts to the Free French naval forces, operating under British control; and eight destroyer escorts to Brazil.
The American destroyer escorts (DEs) were produced in six “classes” or types, five of them quite similar. The frigates (PFs) derived from the British River-class frigate were all of one class, the twin-screw City. In detail: