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Atomic Bomb Development Summary (I)

In 1938 German physicist Otto Hahn discovered how to split the uranium atom. Even though published accounts of the scientific breakthrough prevented keeping this knowledge secret, many scientists feared the Nazis might attempt to manipulate such an advancement to further their attack on the nations of Europe. Hungarian scientist and refugee Leo Szilard shared this apprehension — believing the nuclear energy released during fission could be harnessed to produce bombs capable of severe destruction. Convinced he must act quickly, Szilard persuaded world-renowned physicist Albert Einstein to sign a letter (which Szilard wrote) addressed to President Franklin Delano Roosevelt describing the possible military implications of the German discovery and the urgent need for American research on the subject. Possibly in response to this plea, in addition to the advice of his advisers, FDR appointed the Briggs Committee in October of 1939 to investigate nuclear fission.

The government nonetheless gave little priority to the development of an atomic bomb until the fall of 1941. Sparked by positive results from British scientists studying the feasibility of atomic weapons as well as intelligence reports that the Nazis already had begun tests of their own, FDR authorized an intensive research effort in the United States. The shock of Pearl Harbor and the continued success of the Nazi military campaign in Europe served as reaffirmation that the American government must proceed at full speed to discover the secrets of atomic energy before the Axis Powers.

In June of 1942 the War Department’s Army Corps of Engineers took charge of the effort to develop an atomic bomb. The subsequent top-secret project (code named Manhattan) cultivated a complex, but cooperative relationship between science, industry, the government, and the army. Although research took place across the nation, an obscure lab in Los Alamos, New Mexico became the central site in the effort to produce an atomic weapon. By 1944 both the United States and Great Britain realized Germany no longer had any realistic chance to develop an atomic bomb. Yet instead of slowing the momentum of the Manhattan Project, FDR stressed the need for the continuation of research and development; although Germany failed to pose a viable threat, Japan’s reluctance to surrender signaled the possibility of a long and costly battle in the Pacific. Therefore, the government no longer viewed the bomb as a defensive weapon to protect the world from the Nazis, but as a way to save American lives and money by shortening the war against Japan.

Unaware of the intricacies surrounding the atomic bomb development in the United States, Harry Truman was briefed by presidential advisers concerning the confidential Manhattan Project two weeks after FDR’s death. While at the Potsdam Conference in Germany only a few months later (July 1945) Truman received word of the successful test of an atomic bomb in the New Mexico desert. Until this meeting of the Allied nations, American and British officials failed to disclose any information to Soviet leader Josef Stalin regarding their attempts to build a new weapon. Resentful of the belligerent Soviet foreign policy in Eastern Europe, Truman and Churchill hoped their military secret would provide them with a post-war diplomatic advantage against Stalin. So, although originally conceived as a short-term solution in a military conflict, the atomic bomb eventually evolved into a vital tool of the political maneuvering between the two superpowers that emerged following the Second World War.

Research by Kathleen Johnson,
Volunteer for the Cold War Museum

Works Cited: Bundy, McGeorge. Danger and Survival. New York: Random House, 1988.
Hershberg, James C. James C. Conant. New York: Alfred A. Knopf, 1993.
Stoff, Michael B., Fanton, Jonathan F., Williams, R. Hal, eds. The Manhattan Project.
Philadelphia: Temple University Press, 1991.
Nobile, Philip, ed. Judgment at the Smithsonian. New York: Marlowe & Company, 1995.

To learn more about Japan’s research on atomic weapons, visit Axis History Forum — Atomic plans returned to Japan

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Atomic Bomb Development Summary (II)

Article 2 of 2

On August 2nd 1939, Albert Einstein signed a letter which was addressed to the American President, Franklin D. Roosevelt. In the letter, Einstein revealed that the German government had been working with Uranium with the hope of developing atomic weapons. Fearing that the militaristic nations of Germany and Japan would develop and use these weapons against America or her allies, Roosevelt established the “Uranium Committee” with the purpose of developing atomic weapons. In 1942, the project was handed over to the Army Corps of Engineers and was renamed the “Manhattan project.” Leading the newly renamed project were General Leslie R. Groves (the Army Corps of Engineers’ Deputy Chief of Construction) and the physicist Nels Bohr.

Contrary to popular opinion, the Atomic Bombs produced by the Manhattan Project (Little Boy and Fat Man) were not developed solely at the Los Alamos laboratory facility in New Mexico. In fact, sites around the nation aided in the production of the world’s first atomic weapons, these sites include: the Clinton Engineer Works at Oak Ridge Tennessee, the Hanford Engineer Works in eastern Washington State, Los Alamos (code named “project Y”), and even the University of Chicago in a laboratory under the football stadium. The culmination of these efforts came on July 16th, 1945 when the first atomic bomb was successfully tested at the Los Alamos facility in New Mexico.

Faced with the prospect of an invasion of the Japanese mainland and an estimated 1 million American casualties, President Henry S. Truman decided to deploy atomic weapons on Japan in an effort to force an unconditional surrender. On August 6th, 1945 a B-29 named the Enola Gay dropped the atomic bomb named Little Boy on Hiroshima. In an instant approximately one hundred and thirty-thousand (130,000) Japanese men, women and children were killed, wounded, or disappeared and ninety (90) percent of the city lay in ruin. Lacking an unconditional surrender, Truman ordered the use of the second atomic weapon, Fat Man. On August 9th a B-29 named Bockscar dropped Fat Man on Nagasaki causing an estimated seventy-five thousand (75,000) casualties and leveling one third of the city. After Truman threatened the Japanese with more atomic weapons, Japan surrendered unconditionally on August 14th, 1945, thus ending the Second World War.

By Daniel L. Gordon
Volunteer for the Cold War Museum

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