Timeline of the Manhattan Project

From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army Corps of Engineers.

Over 90% of the cost was for building factories and producing the fissionable materials, with less than 10% for development and production of the weapons.

A relatively simple gun-type fission weapon was made using uranium-235, an isotope that makes up only 0.7 percent of natural uranium.

Reactors were constructed at Oak Ridge and Hanford, Washington, in which uranium was irradiated and transmuted into plutonium.

It includes a number of events prior to the official formation of the Manhattan Project, and a number of events after the atomic bombings of Hiroshima and Nagasaki, until the Manhattan Project was formally replaced by the Atomic Energy Commission in 1947.

A large house with a stone chimney, decorated with bunting. An army officer runs a red and blue flag up a flagpole. In the foreground are two men in suits and one in an army uniform.
Los Alamos Laboratory director Robert Oppenheimer (left), Manhattan Project director Major General Leslie Groves (center) and University of California president Robert Gordon Sproul (right) at the ceremony to present the laboratory with the Army-Navy "E" Award in October 1945
A long corridor with many consoles with dials and switches, attended by women seated on high stools.
Operators at their calutron control panels at Y-12. Gladys Owens, the woman seated in the foreground, did not know what she had been involved with until seeing this photo in a public tour of the facility fifty years later. [ 4 ]
Replica of the Uranverein ' s German experimental nuclear reactor at Haigerloch captured by the Alsos Mission [ 5 ]
Explosive stack of the 100 Ton Test
Video of the Trinity nuclear test
Aircraft of the 509th Composite Group that took part in the bombing of Hiroshima and Nagasaki . Left to right: backup plane, The Great Artiste , Enola Gay
Casing of a Fat Man nuclear bomb, painted like the one dropped on Nagasaki
Aerial view of the mushroom cloud.
Aerial view of the Operation Crossroads Able mushroom cloud rising from the lagoon with the Bikini Island visible in the background