The Manhattan Project was the code name for the U.S. effort during World War II to produce the atomic bomb. The program was under the leadership of Gen. Leslie Groves, and theoretical physicist J. Robert Oppenheimer. The main laboratory was built on an isolated mesa at Los Alamos, New Mexico.

The first atomic bomb was tested at Alamogordo, New Mexico, on July 16, 1945.

See Fission Bomb, Fusion Bomb, CP-1, Hiroshima, Nagasaki, Gun-Type Weapon, Implosion Weapon, Trinity Test.