On 15 August 1941 President Franklin D. Roosevelt authorised the construction of 50 of the new "Evarts"-class design as BDE 1–50 (British destroyer escort) as part of the 1799 program. The turbo-electric powered "Buckley" class were not part of the first order and were authorised later by Public Law 440 effective 6 February 1942. The Royal Navy placed orders in November 1941 with four shipyards: the Boston Navy Yard, the Mare Island Navy Yard, the Philadelphia Naval Shipyard and the Puget Sound Navy Yard. When the United States entered the war, they too adopted the BDE design. The BDE designation was retained by the first six destroyer escorts (BDEs 1, 2, 3, 4, 12 and 46) transferred to the United Kingdom. Of the initial 50 ordered, these were the only ones the Royal Navy received; the rest were reclassified as destroyer escorts (DE) on 25 January 1943 and taken over by the United States Navy. By the end of World War II the Royal Navy had received 32 "Evarts" and 46 "Buckleys" from the Boston Navy Yard, Mare Island Navy Yard and Bethlehem-Hingham.