The Atomic Bomb

Splitting the Atom

Jan 1, 1932

John Crockcroft and E.T.S. Watson split the atom for the first time.

Nuclear Fission reaction

Jan 1, 1934

Enrico Fermi creates the first nuclear fission reaction at the University of Chicago.

Scientists Fleeing

Jan 1, 1937

Many famous scientists such as Albert Einstein, Neils Bohr, and Leo Szilard flee Germany-controlled Europe and immigrate to the US.

Einstein-Szilard Letter

Aug 2, 1939

Leo Szilard drafts a letter explaining to President Roosevelt the dangers of an atomic bomb by Germany, and the need to start research on it. Albert Einstein is coerced into signing it.

WW2

Sep 1, 1939

World War 2 begins with the invasion of Poland by Germany.

FDR's response

Oct 19, 1939

FDR responds back to Albert Einstein, and a committee on uranium is formed as a result.

Advisory Committee on Uranium

Oct 21, 1939

The advisory committee on uranium met to discuss what was mentioned in the letter. They reported back that uranium "would provide a possible source of bombs with a destructiveness vastly greater than anything now known."

Plutonium

Feb 23, 1941

Plutonium is discovered by Glenn T. Seaborg.

Executive Order 8807

Jun 28, 1941

This created the Office of Scientifc Research and Development which was used for large scientific engineering projects. The. main part was the S-1 Uranium Committee.

Atomic Weapons

Oct 9, 1941

FDR allows scientists to begin development of an atomic weapon.

Manhattan Engineering District

Dec 6, 1941

The Manhattan Engineering District is made for creating an atomic weapon. It later becomes known as the Manhattan project.

Pearl Harbor

Dec 7, 1941

Japan attacks Pearl Harbor. The US enters War World 2.

First Controlled Nuclear Reaction

Dec 2, 1942

Enrico Fermi creates the first controlled nuclear fission reaction.

Military Policy Committee

May 5, 1943

The military Policy Committee makes Japan the primary target of future nuclear bombs.

FDR dies

Apr 12, 1945

Franklin Delano Roosevelt dies. Harry Truman becomes President.

War in Europe

May 8, 1945

The War in Europe ends.

Leo Szilard

May 25, 1945

Leo Szilard tries to warn President Truman about the dangers of nuclear weapons.

Japan's Resolve

Jul 13, 1945

American agents discover that Japan will not surrender unconditionally.

Turning Point: Trinity Test

Jul 16, 1945

First atomic bomb is detonated at New Mexico as the Trinity Tes

Truman's Orders

Jul 21, 1945

President Truman orders atomic bombs to be used on Japan.

Potsdam Declaration

Jul 26, 1945

Potsdam Declaration is sent to Japan's unconditional surrender.

Japan's Response

Jul 30, 1945

Japan calls the atomic bomb a hoax and rejects the Potsdam Declaration.

Little Boy

Aug 6, 1945

A uranium gun type bomb called Little Boy is dropped on Hiroshima, Japan. It instantly kills 100,000 people.

First Pamphlets

Aug 7, 1945

US bombers drop pamphlets on Japan about the atomic bomb and the terms of the Potsdam Declaration calling for Japan's surrender.

Fat Man

Aug 9, 1945

Fat Man, a second plutonium bomb was supposed to be dropped in Kokura. However, bad weather caused it to be dropped on Nagasaki instead.

Truman's Speech

Aug 9, 1945

President Truman delivers a speech to the American public detailing the atomic bomb drop on Hiroshima and Nagasaki and the significance of these bombings.

More Pamphlets

Aug 10, 1945

More Pamphlets similar to the first set are dropped following the Nagasaki bombing.

Japan Surrenders

Sep 2, 1945

Japan surrenders. World war 2 is over.The atomic bomb has done its job.

Hydrogen Bomb

Oct 1, 1945

Edward Teller, one of the scientists during the Manhattan Project, asks Oppenheimer to help him build a hydrogen bomb. Oppenheimer refuses.