August 2nd 1939, a letter is drafted by Albert Einstein and fellow Physicist Leo Szilard to be sent to the President, Franklin D Roosevelt (FDR). Preceding this letter a group of leading physicists, including several who had fled Hitler’s Germany, met to discuss their fears of Germany developing a uranium-based weapon.
The physicist Leo Szilard urged Einstein to send the letter to the President expressing the concern that Nazi Germany was working on a new very powerful weapon. In 1938, three chemists working in Berlin made a discovery that would alter the course of history: they split the uranium atom. The energy released when this splitting, or fission, occurs is tremendous – enough to power a bomb if certain technical problems could be solved. When Einstein learned that the Germans might succeed in solving these problems, this prompted him to write the letter.
Letter written by Albert Einstein, with the help of Leo Szilard, to President Franklin Roosevelt on August 2, 1939, warning Roosevelt of the dangers posed by nuclear energy. Credit: Universal History Archive/Universal Images Group 
Leo Szilard (1898 – 1964) Hungarian-American physicist and inventor. Credit: Universal History Archive/Universal Images Group 
Alexander Sachs (August 1 1893 – June 23 1973) was an American economist and banker. In October 1939 he delivered the Einstein-Szilard letter to President Franklin D. Roosevelt. Credit: Universal History Archive/Universal Images Group 
Franklin Roosevelt signing Beer Bill ca. 1933. Credit: HUM Images/Universal Images Group 
Physicists, J. Robert Oppenheimer and Gregory Breit. Credit: Universal History Archive/Universal Images Group 
Germany / USA: Albert Einstein (1879-1955) receiving his Certificate of American Citizenship from Judge Phillip Forman, 1 October 1940. Credit: Pictures From History/Universal Images Group 
USA: Robert Oppenheimer (1904-1967), theoretical physicist and as a member of the Manhattan Project, ‘father of the atomic bomb’, Oak Ridge, circa 1946. Credit: Pictures From History/Universal Images Group
Because Albert Einstein had a previous personal relationship with the Roosevelts and was internationally well-known for his expertise, a letter informing the President about the dangers of a nuclear chain reaction bomb was drafted for Einstein’s signature. This August 2, 1939 letter was personally delivered to the President on October 11, 1939 (the outbreak of the war intervened) by Alexander Sachs, a longtime economic adviser to FDR. After learning the letter’s contents, President Roosevelt told his military adviser General Edwin M. Watson, “This requires action.”
The Gadget, the first atomic bomb tested in Nevada USA, 1945. Credit: Photo12/Universal Images Group 
Los Alamos, New Mexico, July 16, 1945 The world’s first atomic bomb was detonated atop this tower at the Trinity Site in New Mexico. Credit: Underwood Archives/Universal Images Group 
Atomic bomb explosion fireball. Camp Mercury, Yucca Flats, Nevada, 1957. Credit: GG Vintage Images/Universal Images Group 
1952 – Pfc Jack Wilson (left center) and Sgt. Glenn Poth gaze a the atomic cloud at about two minutes after detonation on Shot Day. White streak is a censor’s mark. Credit: GG Vintage Images/Universal Images Group 
The first atomic bomb was test detonated at Trinity Site. Credit: Universal History Archive/Universal Images Group 
Los Alamos, New Mexico, July 16, 1945 The Trinity fireball, 15 seconds after the detonation of the first atomic bomb, rises into the air above the desert. Credit: Underwood Archives/Universal Images Group 
D-Reactor complex, Area 100-D, constructed during Manhattan Project and World War II, Richland, Benton County, Washington, USA, Historic American Engineering Record. Credit: Circa Images/GHI/Universal History Archive/Universal Images Group 
United States detonating an atomic bomb at Bikini Atoll in Micronesia for the first underwater test of the device in 1946. Credit: Photo12/Universal Images Group 
July 16, 1945 – The “Trinity” Test Fireball – Test of the first atomic bomb in New Mexico as part of the Manhattan Project. Credit: GG Vintage Images/Universal Images Group 
Robert Oppenheimer and General Groves at the atomic bomb, Trinity Test site. Credit: Universal History Archive/Universal Images Group
Two other findings in 1940 and 1941 demonstrated conclusively that the bomb was feasible and made building the bomb a top priority for the United States and in December 1941, the government launched the Manhattan Project, the scientific and military undertaking to develop the bomb.
All images featured in this post and on Kaleidoscope are available for licensing. Please contact us at info@universalimagesgroup.com
Sources:
http://www.fdrlibrary.marist.edu/archives/pdfs/docsworldwar.pdf