The Manhattan Project, An Interactive History Home The Manhattan Project, An Interactive History Home Department of Energy Home Office of History and Heritage Resources Home DOEHome
J.R. Oppenheimer and General Groves
Events People Places Processes Science Resources

Time Periods

1890s-1939:
Atomic Discoveries

1939-1942:
Early
Government Support

1942:
Difficult
Choices

1942-1944:
The Uranium
Path to
the Bomb

1942-1944:
The Plutonium
Path to
the Bomb

1942-1945:
Bringing It All Together

1945:
Dawn of the
Atomic Era

1945-present:
Postscript --
The Nuclear Age

Albert Einstein and Leo SzilardEARLY GOVERNMENT SUPPORT
(1939-1942)
Events

As the news of the fission breakthrough spread from Berlin in early 1939, many physicists within the United States (and elsewhere) immediately realized the potential danger posed by atomic energy.  Especially concerned were émigré physicists who had fled their native countries because of the expansion of Nazi Germany and sought to obtain governmental support for further, secret nuclear research.  Convincing busy government officials of the seriousness of this esoteric new scientific development was at first slow going.  One month before the Second World War formally began with the September 1, 1939, invasion of Poland by Nazi Germany, Leo Szilard enlisted the help of Albert Einstein in personally calling President Franklin Roosevelt's attention to the matter.  Roosevelt responded by creating a government committee to coordinate and provide modest funding for early uranium research.  Work also proceeded during this period on the design of an atomic pile that could demonstrate the potential of atomic energy and possibly provide a second path to the atomic bomb besides uranium.  

Key administrators of the Manhattan Project meet at Berkeley, March 29, 1940.Following the rapid successes of the German armies in Europe in 1940, many scientists felt that it was only a matter of time before the United States became involved in the war.  They argued that reorganization and acceleration of atomic research was vital if a bomb was to be produced in time to affect the war.  This belief was strengthened by the MAUD Report, the latest and most influential in a series of studies that argued that an atomic bomb was feasible.  The surprise Japanese attack on Pearl Harbor of December 7, 1941, catapulted the United States into the war, and the following month Roosevelt secretly gave his tentative approval to proceed with the construction of an atomic bomb.

President Roosevelt signs declaration of war with Japan, December 8, 1941.To learn more about any of these events associated with early government support of atomic research, choose a web page from the menu below.  To continue with a quick overview of the Manhattan Project, jump ahead to the description of the "Difficult Choices" that had to be made in 1942 regarding what would soon be known as the "Manhattan Project.

Previous    Next


Sources and notes for this page.

The text for this page is original to the Department of Energy's Office of History and Heritage Resources.  The photograph of Albert Einstein with Leo Szilard is courtesy the Federation of American Scientists.  Click here for information on the photograph of the 1940 meeting at Berkeley.  The photograph of President Franklin Roosevelt signing the declaration of war on Japan, December 8, 1941, is courtesy the National Archives.

Home | History Office | OpenNet | DOE | Privacy and Security Notices
About this Site | How to Navigate this Site | Note on Sources | Site Map | Contact Us