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Colonel James Marshall, 1946GROVES AND THE MED
Events > Difficult Choices, 1942

The summer of 1942 proved to be a troublesome one for the fledgling bomb project.  Colonel James C. Marshall (right) received the assignment of directing the Laboratory for the Development of Substitute Metals, or DSM, the military’s initial cover name for the project.  Marshall immediately moved from Syracuse, where he served in the Corps’s Syracuse Engineer District, to New York City. Concerned that the name DSM would attract too much attention, the military set up the Manhattan Engineer District (MED), established by general order on August 13. Marshall, like most other Army officers, knew nothing of nuclear physics.  Furthermore, Marshall and his Army superiors were disposed to move cautiously. In one case, for instance, Marshall delayed purchase of an excellent production site in Tennessee pending further study, while the scientists who had been involved in the project from the start were pressing for immediate purchase. Although Vannevar Bush had carefully managed the transition to Army control, there was not yet a mechanism to arbitrate disagreements between the S-1 Committee and the military.  The resulting lack of coordination complicated attempts to gain a higher priority for scarce materials and boded ill for the future of the entire bomb project.

Leslie Groves, Commanding General of the Manhattan Engineer DistrictIn September, Bush and the Army agreed that an officer other than Marshall should be given the assignment of overseeing the entire atomic project, which by now was referred to as the Manhattan Project.  On September 17, the Army appointed Colonel Leslie R. Groves (left) to head the effort.  Six days late, he was promoted to Brigadier General.  Groves was an engineer with impressive credentials, including building of the Pentagon, and, most importantly, had strong administrative abilities.  Within two days, Groves acted to obtain the Tennessee site and secured a higher priority rating for project materials.  In addition, Groves moved the Manhattan Engineer District headquarters from New York to Washington.  He quickly recognized the talents of Marshall's deputy, Colonel Kenneth D. Nichols, and arranged for Nichols to work as his chief aide and troubleshooter throughout the war.

Vannevar Bush, James Conant, Groves, and Franklin Matthias, Hanford, WashingtonMeanwhile Bush, with the help and authority of Secretary of War Henry L. Stimson, set up the Military Policy Committee, including one representative each from the Army, the Navy, and the Office of Scientific Research and Development.  Bush hoped that scientists would have better access to decision making in the new structure than they had enjoyed when DSM and S-1 operated as parallel but separate units.  With Groves in overall command (Marshall remained as District Engineer, where his cautious nature proved useful in later decision making) and the Military Policy Committee in place (the Top Policy Group retained broad policy authority), Bush felt that early organizational deficiencies had been remedied.  In October 1942, Groves also accepted the suggestion forwarded by Robert Oppenheimer and others to concentrate in an isolated location all research on the design of the bombs themselves.  The search soon began for the site of what would become the Los Alamos laboratory.  

Leslie Groves and J. Robert OppenheimerDuring summer and fall 1942, technical and administrative difficulties were still severe.  Each of the four processes for producing fissionable material for a bomb remained under consideration, but a full-scale commitment to all four posed serious problems, even with the project's high priority.  When Groves took command in mid-September, he made it clear that by late 1942 decisions would be made as to which process or processes promised to produce a bomb in the shortest amount of time.  The exigencies of war, Groves held, required scientists to move from laboratory research to development and production in record time.  Though traditional scientific caution might be short-circuited in the process, there was no alternative if a bomb was to be built in time to be used in the current conflict.  As everyone involved in the Manhattan Project soon learned, Groves never lost sight of this goal and made all his decisions accordingly.

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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), 13-14, 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), 82-83.  The photograph of James Marshall and the photograph of Leslie Groves are reprinted from page 42 and the inside front cover, respectively, of 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).  The photograph of Vannevar Bush, James Conant, Groves, and Franklin Matthias is courtesy the DuPont Corporation; it is reprinted in Stephane Groueff, Manhattan Project: The Untold Story of the Making of the Atomic Bomb (Boston: Little, Brown, and Company, 1967).  The photograph of Groves with Robert Oppenheimer is courtesy the Department of Energy.

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