History

History

This section provides an overview of the history of the Manhattan Project, the key organizations involved, the science behind the bomb, and more.
Bravo thermonuclear test

Hydrogen Bomb - 1950

In January 1950, President Truman made the controversial decision to continue and intensify research and production of thermonuclear weapons.

Isotope Separation Methods

How to separate the much more potent U-235 from its abundant relative, U-238 consumed thousands of hours and millions of dollars.
Japanese Relocation Notice

Japanese American Relocation and Internment Camps

In the aftermath of the attack on Pearl Harbor, President Roosevelt ordered the "evacuation" of Japanese Americans to relocation and internment camps under Executive Order 9066.
A Japanese cyclotron constructed after the war

Japanese Atomic Bomb Project

Japan initiated multiple small efforts to pursue an atomic bomb, but all were unsuccessful.
Photo courtesy of the National Archives and Records Administration

Japanese Balloon Bombs "Fu-Go"

On November 3, 1944, Japan released fusen bakudan, or balloon bombs, into the Pacific jet stream. Japan’s latest weapon, the balloon bombs were intended to cause damage and spread panic in the continental United States.
Japanese resistance fighters captured

Japanese Mass Suicides

The War of the Pacific against Imperial Japan was marked by episodes of mass suicides by Japanese soldiers and civilians, notably in Saipan and Okinawa.
Jumbo on train

Jumbo

Jumbo was designed by Los Alamos lab to act as a failsafe device for the Trinity test explosion.
Leo Szilard. Image courtesy of Argonne National Laboratory.

Leo Szilard's Fight to Stop the Bomb

Hungarian-American physicist Leo Szilard's petition sought to avert use of the atomic bombs against Japan.
Kennedy signs the LTBT

Limited or Partial Test Ban Treaty (LTBT/PTBT)

The Limited Test Ban Treaty (LTBT), also known as the Partial Test Ban Treaty (PTBT), is an arms control agreement intended to restrict the testing of nuclear weapons and limit nuclear proliferation.

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