Untitled timeline

Main

World War II Begins

September 1, 1939

Groves and Oppenheimer placed see notes

Approx. September 23, 1941

olonel Leslie Groves is placed in charge of the Manhattan Project. J. Robert Oppenheimer becomes the Project's Scientific Director.

FDR gives the go-ahead for the development of an atomic weapon.

Approx. October 9, 1941

FDR authorizes the Manhattan Engineering District to create atomic bomb.

Approx. December 6, 1941

Military Policy Committee of Manhattan Project choses Japan as target for bomb

Approx. May 5, 1943

Franklin Roosevelt dies. Harry Truman named the 33rd President of the US.

Approx. April 12, 1945

War ends in Europe.

May 8, 1945

The world's first atomic detonation takes place see notes

July 16, 1945

in the 'Trinity Test' at Alamogordo, New Mexico.

President Truman orders atomic bombs to be used.

July 21, 1945

Little Boy is detonated over Hiroshima, Japan

August 6, 1945

U.S. decides to drop warning pamphlets on Japanese cities.

August 7, 1945

Fat Man dropped on Nagasaki

August 9, 1945

Japan announces formal surrender

September 2, 1945