The code name for the American project set up in 1942 to develop an atom bomb. The project culminated in 1945 with the detonation of the first nuclear weapon, at White Sands in New Mexico.
Definition of Manhattan Project in US English:
Manhattan Project
proper noun
The code name for the American project set up in 1942 to develop an atom bomb. The project culminated in 1945 with the detonation of the first nuclear weapon, at White Sands in New Mexico.