The Manhattan Project

Sites and Their Contributions · Key Events · Scientists · Its Story · Additional Information · Related Information

President Roosevelt Establishes the
Manhattan Project

President Roosevelt instructs the Army to take responsibility for construction of atomic weapons complex. The Army delegates the task to the Corps of Engineers, which establishes the Manhattan Engineer District.
Courtesy of National Nuclear
Security Administration

August 13, 2012 was the 70th anniversary of the establishment of the Manhattan Project.  The Manhattan Project played an essential role in bringing World War II to an end through the building of the atomic bomb.  This major achievement was possible because the U.S. government conducted a massive, secret, nationwide enterprise that took science from the laboratory and into combat with an entirely new type of weapon.

Three primary sites were chosen to be the locations for this effort, with other sites playing key roles.  Many renowned scientists from both the United States and abroad combined their extensive knowledge and expertise to meet the challenges of doing great work in a very short period of time.  After the end of the war, the United States directed efforts towards peaceful uses of atomic energy.

The Manhattan Project is a predecessor of the U.S. Department of Energy.

The Sites and Their Contributions:


Key Events:

August 2, 1939 -- Albert Einstein's Letter to President Franklin D. Roosevelt
January 19, 1942 -- President Roosevelt Approves Production of Atomic Bomb

August 13, 1942 -- Manhattan Engineer District is established

December 2, 1942 -- First Self-sustaining Nuclear Chain Reaction
August 6, 1945 -- Little Boy Dropped on Hiroshima

August 9, 1945 -- Fat Man Dropped on Nagasaki

September 2, 1945 -- Japan Signs Official Instrument of Surrender

December 8, 1953 -- Atoms for Peace Speech
December 19, 2014 -- Manhattan Project National Historical Park authorized




Additional Information:


Related Information:


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