The Manhattan Engineer District was officially designated as such by the U.S. War Department on August 13, 1942. Also known as the Manhattan Project and initially headquartered in New York, it functioned as a special district for directing the atomic bomb project. It supervised research, development, and testing of projects, plant construction, and production programs relating to the project and administered numerous laboratories and field installations including Clinton Engineer Works at Oak Ridge, TN; Hanford Engineer Works at Richland, WA; and the laboratory at Los Alamos, NM. On December 31, 1946 the Armed Forces Special Weapons Project was established to assume the military functions of the Manhattan Engineer District and on January 1, 1947 all phases of nuclear energy research and production came under control of the U.S. Atomic Energy Commission. The Manhattan Engineer District continued for about six months longer solely as an administrative agency to close out the project.