Manhattan Project

Manhattan Project, the wartime effort to design and build the first nuclear weapons (atomic bombs). With the discovery of fission in 1939, it became clear to scientists that certain radioactive materials could be used to make a bomb of unprecented power. U.S. President Franklin Delano Roosevelt responded by creating the Uranium Committee to investigate this possibility. Progress was slow until Aug., 1942, when the project was placed under U.S. Army control and reorganized. The Manhattan Engineer District (MED) was the official name of the project. The MED's commanding officer, Gen. Leslie R. Groves, was given almost unlimited powers to call upon the military, industrial, and scientific resources of the nation.

A $2-billion effort was required to obtain sufficient amounts of the two necessary isotopes, uranium-235 and plutonium-239. At Oak Ridge, Tenn., the desired uranium-235 was separated from the much more abundant uranium-238 by a laborious process called gaseous diffusion. At the Hanford installation (Wash.), huge nuclear reactors were built to transmute nonfissionable uranium-238 into plutonium-239. This method was based on the principle of the self-sustaining nuclear reaction (nuclear pile) that had first been achieved under the leadership of Enrico Fermi at the metallurgical laboratory of the Univ. of Chicago. At the radiation laboratory of the Univ. of California at Berkeley costly efforts were made to separate the two uranium isotopes using cyclotrons, but only about a gram of pure uranium-235 was obtained. The actual design and building of the plutonium and uranium bombs took place at Los Alamos, N.Mex., under the leadership of J. Robert Oppenheimer. Gathered at this desert laboratory was an extraordinary group of American and European-refugee scientists.

The only nuclear test explosion, code-named Trinity, was of a plutonium device; it took place on July 16, 1945, near Alamogordo, N.Mex. The first uranium bomb ( "Little Boy" ) was delivered untested to the army and was dropped on Hiroshima on Aug. 6, 1945, killing at least 70,000 inhabitants. On Aug. 9, 1945, a plutonium bomb virtually identical to the Trinity device was dropped on Nagasaki, killing at least 35,000 inhabitants.

See L. R. Groves, Now It Can Be Told (1962); L. Lamont, Day of Trinity (1965); H. Feis, The Atomic Bomb and the End of World War II (rev. ed. 1966); R. Rhodes, The Making of the Atomic Bomb (1987); R. S. Norris, Racing for the Bomb (2002).

The Columbia Encyclopedia, 6th ed. Copyright© 2018, The Columbia University Press.

Manhattan Project: Selected full-text books and articles

Nuclear America: Military and Civilian Nuclear Power in the United States, 1940-1980 By Gerard H. Clarfield; William M. Wiecek Harper & Row, 1984
Librarian's tip: Chap. 2 "The Radiance of a Thousand Suns: Development of the Atomic Bomb During World War II"
The American Atom: A Documentary History of Nuclear Policies from the Discovery of Fission to the Present, 1939-1984 By Robert C. Williams; Philip L. Cantelon University of Pennsylvania Press, 1984
Librarian's tip: Part II "The Manhattan Project"
A primary source is a work that is being studied, or that provides first-hand or direct evidence on a topic. Common types of primary sources include works of literature, historical documents, original philosophical writings, and religious texts.
In the Matter of J. Robert Oppenheimer: Politics, Rhetoric, and Self-Defense By Rachel L. Holloway Praeger Publishers, 1993
Librarian's tip: "The Los Alamos Years: Oppenheimer 'Fathers' The Atomic Bomb" begins on p. 18
The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman By Richard P. Feynman; Jeffrey Robbins Helix Books, 2000
Librarian's tip: Chap. 3 "Los Almos from Below"
On Rims & Ridges: The Los Alamos Area since 1880 By Hal K. Rothman University of Nebraska Press, 1992
Librarian's tip: Chap. 10 "Barbed Wire and Watch Towers"
For Better or for Worse: The Marriage of Science and Government in the United States By Alfred K. Mann Columbia University Press, 2000
Librarian's tip: "The Other Major Organizations for Science and Technology in WWII Was the Manhattan Project, the Single Purpose of Which Was to Produce an Atomic Bomb" begins on p. 18
Secret Science: Federal Control of American Science and Technology By Herbert N. Foerstel Praeger Publishers, 1993
Librarian's tip: Chap. 3 "Atomic Secrets"
American Science in an Age of Anxiety: Scientists, Anticommunism, and the Cold War By Jessica Wang University of North Carolina Press, 1999
Librarian's tip: "Eugene Rabinowitch" begins on p. 89
Beyond Engineering: How Society Shapes Technology By Robert Pool Oxford University Press, 1997
Librarian's tip: Chap. 1 "History and Momentus"
Organizing Genius: The Secrets of Creative Collaboration By Warren Bennis; Patricia Ward Biederman Perseus Books, 1997
Librarian's tip: "The Manhattan Project" begins on p. 171
Historical Encyclopedia of Atomic Energy By Stephen E. Atkins Greenwood Press, 2000
Librarian's tip: "Manhattan Project" begins on p. 223
Looking for a topic idea? Use Questia's Topic Generator
Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.