MANHATTAN PROJECT

The Manhattan Engineer District, a secret U.S. government project begun in 1942 to develop an atomic bomb, was managed by Brigadier General Leslie Groves and undertaken by the U.S. Army Corps of Engineers. Under-taken at the urging of physicists Leo Szilard, Eugene Wigner, Edward Teller, Enrico Fermi, and Albert Einstein, the project responded to the threat of atomic weapon development by Nazi Germany. Ultimately, the U.S. effort brought together intelligence operatives, leading physicists, chemists, and engineers, as well as thousands of managers and workers at four major sites.

The best known of these sites, Los Alamos, in New Mexico, was the scientific and design headquarters of the project. Directed by the physicist J. Robert Oppenheimer, the Los Alamos site developed the theoretical knowledge behind the bomb and pieced together the designs for the two types of devices used on the Japanese cities of Hiroshima—a uranium bomb (code-named Little Boy)—and Nagasaki—a plutonium device (code-named Fat Man)—in August 1945.

However, the lesser known sites, such as the Radiation Laboratory in Berkeley, California, the Metallurgical Laboratory at the University of Chicago, and the two atomic manufacturing centers, Oak Ridge, Tennessee, and Hanford, Washington, each made major contributions to the Manhattan Project as well. Berkeley's laboratory, the product of Ernest Lawrence's work on the physics of radiation, produced the theoretical and practical knowledge that drove the electromagnetic separation process in Oak Ridge. The Metallurgical Laboratory in Chicago, headed by Arthur Compton, created the first chain reaction, and established a pilot plant for the manufacture of plutonium, built in Oak Ridge.

Full-scale uranium separation took place in the massive industrial facilities of Oak Ridge, Tennessee. Built as a secret city, the facility drew workers from throughout Appalachia and the South with high wages and promises of housing and a better life. At the three major plants of Oak Ridge—chemical separations (K-25), electromagnetic separations (Y-12), and the plutonium pilot plant (X-10)—engineers, managers, and workers struggled to produce atomic material pure enough to power the bombs being designed and assembled at Los Alamos. The Hanford, Washington, site, built and managed by the Du Pont Corporation, comprised massive camps of workers building and manning a facility to

THE TECHNOLOGY OF WORLD WARS I AND II

War has always driven technological advances. United States involvement in the two great global conflicts of the twentieth century impelled the development of weapons of a hitherto unsurpassed efficacy and sophistication. Many of the weapons developed for World War I saw their genesis in the nineteenth century and remain in use in the twenty-first.

The Springfield 1903 Rifle

The Springfield was a bolt-action (single-shot) rifle was issued to United States troops during World War I, and was in wide use during the first half of the twentieth century. The Springfield 1903 was developed after observation of weapons used during the Spanish-American War (1898). Spanish troops were armed with German Mauser 98 rifles, which were superior in many ways to those available to U.S. troops. A prototype of the Springfield was developed in 1900 and went into production in 1903 at the federally-owned Springfield Armory in Geneseo, Illinois. The gun was adapted for German-style pointed ammunition—the Springfield rounds, designated "Cartridge, Ball, Caliber .30, Model of 1906," led to the term .30-'06 (or "thirty-ought six"); this ammunition is used in countless small arms in the twenty-first century. The Springfield was so obviously modeled on the German Mauser that the U.S. government had to pay royalties to the German manufacturer Mauserwerke.

The M1 Garand

The federally-owned Springfield Armory in Geneseo was also the site of the development of the only full-power, semiautomatic standard infantry rifle used during World War II. This rifle replaced the Springfield due to its superior speed of fire—it was a clip-loading rather than a bolt-action weapon, and therefore could be fired multiple times before needing to be reloaded. The M1 Garand remains the most popular high-powered target semiautomatic in the world into the twenty-first century.

The Norden Bombsight

The Norden Bombsight (NBS), an optical precision device used to target bombs from aircraft to ground locations much more accurately than had before been possible, was one of the most secret weapons developed and used by the U.S. before and during World War II. Before it was introduced, there was no precise way to guide bombs to specific targets. Bombardiers simply dropped bombs near their intended targets. "Carpet bombing" and the "Blitzkreig" approach of bombing enemy territory guaranteed a high rate of destruction and massive civilian casualties. The Navy Bureau of Ordnance began development of the NBS in 1922. In 1932 the prototype Mark XV was introduced, and the configuration of the NBS was largely unchanged throughout its functional life. Its accuracy during Allied bombing runs made it one of the most important technical developments of World War II. It was used with the first guided bombs—the forerunners of the guided missile. The NBS was used in 1967 and 1968 in the Vietnam War before it was superceded by more accurate equipment.

The Army Signal Corps was the source of most developments in the nation's communications and electronics technology in World War II. In World War I, wire had proven its worth as a communications tool and was used in most tactical and administrative signal equipment. Radio did not lend itself to secrecy and had serious drawbacks in reliability and ease of use, and in the 1930s the Signal Corps focused on researching long-range radio capabilities. The laboratories developed compact switchboards for corps and division levels. Work on a military version of the teletype printer also began, as did development of the military field typewriter. The Army Signal Corps worked to decrease the size of vehicular radios that had to be removed and set up on the ground; infantry, cavalry, and armored divisions suffered the limitations of the equipment's stationary ground use and limited range. Equipment weight was a major concern, along with limited wave range. Navigational radio emerged from World War I: it could be used for intelligence gathering or as a means of taking bearings from fixed radio sites. This concept, first used in ships and planes, has been refined throughout the twentieth century and into the twenty-first to such a degree that it can be used by individuals and has been installed in commercially manufactured automobiles.

Marie Lazzari

create plutonium, a man-made element, for use in the Fat Man device.

Secrecy was the watchword of the project, both among workers and scientists. General Groves' system of compartmentalization meant that almost all project employees, military or civilian, had knowledge of only their small piece of the atomic puzzle, with no overview of how the entire project fit together. However, some information did make its way to the Soviet Union before the close of the war, through the efforts of Soviet agents like Los Alamos physicist Klaus Fuchs.

After the successful atomic test at Alamogordo, New Mexico, on July 16, 1945, the atomic bomb became an important implement of U.S. military and diplomatic policy. At the summit of American, British, and Soviet leaders in Potsdam, Germany, in July-August 1945, President Harry Truman warned an unsurprised Joseph Stalin of the existence of a powerful new weapon. However, the August 6, 1945, dropping of the atomic bomb on Hiroshima took the world (and many Manhattan Project personnel) by surprise. The dropping of the second bomb two days later, on August 8, demonstrated that America was willing and able to use atomic weapons again to bring about Japanese capitulation.

The decision to use the atomic bomb was made by President Truman, against the advice of scientists such as James Franck, who urged the U.S. government to warn Japan first about the atomic bomb, or to demonstrate the bomb for Japanese observers first.

The U.S. sought a target area for the bombs that would hamper the Japanese war effort and provide the Japanese with a full demonstration of the bomb's devastation. Secretary of War Henry Stimson vetoed the consideration of Kyoto as a target because of its cultural value to the Japanese people. Two cities not yet bombed, Hiroshima and Nagasaki, both major cities with military ports, were chosen instead as the first targets for the atomic bombs.

After the bombs' detonations, the wartime Japanese government, at the command of Emperor Hirohito, abandoned its plan for massive resistance to U.S. invasion and surrendered on August 14, 1945. The devastation of the bombing, which killed more than 60,000 in Hiroshima and more than 30,000 in Nagasaki, would become known only in the weeks to come. More than 100,000 people injured by the atomic bombs' blasts and radiation were forced to cope with its impact for the rest of their lives.

The significance of the Manhattan Project has been assessed from various perspectives. The historian David Kennedy has written, in Freedom from Fear, that the Project

stands as the single best illustration of the American way of war—not so much for the technological novelty of the bombs, or the moral issues they inevitably raised, but because only the Americans had the margins of money, material, and manpower, as well as the undisturbed space and time, to bring an enterprise on the scale of the Manhattan Project to successful completion. (p. 668)

On the other hand, the Project forever changed warfare, international relations, and America's sense of security. Atomic weapons in the hands of governments or terrorists created the possibility of a nuclear holocaust. That specter of mass destruction would not only affect America's defense policy but also help to shape the nation's postwar society and culture.

bibliography

Kennedy, David M. Freedom from Fear: The American People in Depression and War, 1929–1945. New York: Oxford University Press, 1999.

Boyer, Paul. By the Bomb's Early Light: American Thought and Culture at the Dawn of the Atomic Age. NY: Pantheon Books, 1985.

Committee for the Compilation of Materials on Damage Caused by the Atomic Bombs at Hiroshima and Nagasaki. The Physical, Medical, and Social Effects of the Atomic Bombings. New York: Basic Books, 1981.

Groueff, Stephane. Manhattan Project: The Untold Story of the Making of the Atomic Bomb. Boston: Little, Brown and Co., 1967.

Groves, Leslie. Now it Can Be Told. New York: Harper and Row, 1962.

Jones, Vincent. Manhattan: The Army and the Atomic Bomb. Washington, D.C.: United States Army, 1985.

Sherwin, Martin. A World Destroyed. New York, Vintage, 1987.

Russell Olwell