Manhattan Project: Enter the Army, 1942

Time Periods

1890s-1939:
Atomic Discoveries

1939-1942:
Early
Government Support

1942:
Difficult
Choices

1942-1944:
The Uranium
Path to
the Bomb

1942-1944:
The Plutonium
Path to
the Bomb

1942-1945:
Bringing It All Together

1945:
Dawn of the
Atomic Era

1945-present:
Postscript --
The Nuclear Age

ENTER THE ARMY
(1942)
Events > Difficult Choices, 1942

The decision to proceed with planning for the production of enriched uranium and of plutonium led directly to the involvement of the Army, specifically the Corps of Engineers. President Roosevelt had approved Army involvement on October 9, 1941, and Vannevar Bush had arranged for Army participation at S-1 meetings beginning in March 1942. The need for security suggested placing the S-1 program within one of the armed forces, and the construction expertise of the Corps of Engineers made it the logical choice to build the production facilities envisioned in the Conant report of May 23.

By orchestrating some delicate negotiations between the Office of Scientific Research and Development (OSRD) and the Army, Bush was able to transfer the responsibility for process development, materials procurement, engineering design, and site selection to the Corps of Engineers and to earmark approximately sixty percent of the proposed 1943 budget, or $54 million, for these functions. An Army officer would be in overall command of the entire project. This new arrangement left S-1, with a budget of approximately $30 million, in charge of only university research and pilot plant studies. Additional reorganization created an S-1 Executive Committee (above), composed of James Conant, Lyman Briggs, Arthur Compton, Ernest Lawrence, Eger Murphree, and Harold Urey. This group would oversee all OSRD work and keep abreast of technical developments that might influence engineering considerations or plant design. With this reorganization in place, the nature of the American atomic bomb effort changed from one dominated by research scientists to one in which scientists played a supporting role in a construction enterprise run by the United States Army Corps of Engineers.

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Sources and notes for this page.

The text for this page was adapted from, and portions were taken directly from the Office of History and Heritage Resources publications: F. G. Gosling, The Manhattan Project: Making the Atomic Bomb (DOE/MA-0001; Washington: History Division, Department of Energy, January 1999), 11-12, and Richard G. Hewlett and Oscar E. Anderson, Jr., The New World, 1939-1946: Volume I, A History of the United States Atomic Energy Commission (Washington: U.S. Atomic Energy Commission, 1972), 74-75. The photograph of the military parade at Los Alamos is courtesy Colonel Gerald T. Tyler; it is reprinted from Vincent C. Jones, Manhattan: The Army and the Atomic Bomb, United States Army in World War II (Washington: Center of Military History, United States Army, 1988), 361. Click here for more information on the photograph of the S-1 (Uranium) Committee.