Manhattan Engineer District – USAEC

In 1943, General Leslie R. Groves, commander of the Manhattan Project, delegated to Colonel Kenneth D. Nichols responsibility for administering what became a $2.2 billion effort. Nichols had his headquarters here in a rambling, seven-wing frame building where the Federal Building now stands, known as “The Castle,” and ran both the project here and much of the national effort. Throughout the war, the Army identified technically trained soldiers serving elsewhere and reassigned them to the project, and they made important contributions in Oak Ridge, Hanford, and Los Alamos. The Special Engineer Detachment here included 1,257 men, and a detachment of the Women’s Army Corps also served here. Shortly after the war, Nichols wrote that the Manhattan Project was an accomplishment that would endure as a monument to the ingenuity, vision, and determination of all those, from scientists to laborers, who had a part in the work, and that these people and their organizations deserved unlimited credit for successfully accomplishing an almost impossibly vast and complicated task. In 1947, operations were transferred to civilian control with the creation of the U.S. Atomic Energy Commission, which for the next three decades managed its national defense mission and the application of nuclear science to medicine, agriculture, industry, and energy. The AEC became a predecessor agency of the U.S. Department of Energy, a cabinet-level agency responsible for programs in national security, science and technology, energy security, and environmental management.

Oak Ridge, Tennessee · United States