This section provides an overview of the history of the Manhattan Project, the key organizations involved, the science behind the bomb, and more.
Castle Bravo. Image courtesy of Los Alamos National Laboratory.

Castle Bravo

On March 1, 1954, the United States carried out its largest nuclear detonation, “Castle Bravo,” at Bikini Atoll in the Marshall Islands. The Bravo explosion was more than two and a half times greater than expected and caused far higher levels of fallout and damage than scientists had predicted.
Graphite blocks

Chicago Pile-1

On December 2, 1942, Chicago Pile-1 went critical, creating the world’s first controlled, self-sustaining nuclear chain reaction.
Joe-1 nuclear test

Cold War

The Cold War began shortly after WWII and plunged the world into a series of conflicts that would last more than forty years.

Combined Development Trust

The Combined Development Trust (CDT) was an effort spearheaded by General Leslie Groves to control the world market of uranium ore.
J. Robert Oppenheimer, John Von Neumann, and the MANIAC computer. Courtesy of the Shelby White and Leon Levy Archives Center, Institute for Advanced Study (IAS). © Alan Richards.

Computing and the Manhattan Project

The development of early computing benefited enormously from the Manhattan Project’s innovation.
Enola Gay - Smithsonian Institute Archives

Controversy over the Enola Gay Exhibition

For the 50th anniversary of the end of World War II, the National Air and Space Museum proposed a controversial exhibition that displayed the Enola Gay.

Corporate Partners

Perhaps one of the most intriguing stories to come out of the Manhattan Project was the partnerships formed by the military, the scientific community, and some of America's foremost corporations.
Hiroshima's financial district after the bombing

Debate over the Bomb

One of the greatest controversies to come out of World War II was whether the atomic bomb was necessary to bring about its end.
The mushroom cloud over Nagasaki

Debate over the Bomb: An Annotated Bibliography

A list of books and articles provide a range of perspectives on the atomic bombings.