September 30, 2021
For educational institutions
⟶ Updated 11 Oct 2018 ⟶
List of edits
Albert Einstein writes to President Franklin Roosevelt concerning the use of uranium as a new source of energy leading to the formation of the Committee on Uranium.
Plutonium is discovered by Glenn Seaborg.
FDR gives the go-ahead for the development of an atomic weapon.
FDR authorizes the Manhattan Engineering District for the purpose of creating an atomic bomb. This would later be called the 'Manhattan Project'.
Colonel Leslie Groves is placed in charge of the Manhattan Project. J. Robert Oppenheimer becomes the Project's Scientific Director.
First controlled nuclear fission reaction is produced by Enrico Fermi at the University of Chicago.
Japan becomes the primary target for any future atomic bomb according to the Military Policy Committee of the Manhattan Project.
Franklin Roosevelt dies. Harry Truman is named the 33rd President of the US.
The Target Committee of the Manhattan Project select four cities as possible targets for the atomic bomb. They are: Kyoto, Hiroshima, Kokura, and Niigata.
War ends in Europe.
Leo Szilard attempts to warn President Truman in person concerning the dangers of atomic weapons.
Leo Szilard begins a petition to get President Truman to call off using the atomic bomb in Japan.
American intelligence discovers the only obstacle to peace with Japan is 'unconditional surrender'.
The world's first atomic detonation takes place in the 'Trinity Test' at Alamogordo, New Mexico.
President Truman orders atomic bombs to be used.
Little Boy, a uranium bomb, is detonated over Hiroshima, Japan.
The second atomic bomb to hit Japan, Fat Man, was scheduled to be dropped at Kokura. However, because of poor weather the target was moved to Nagasaki.
Japan announces its formal surrender.
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