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.
Foreign Minister Shigemitsu signs the Instrument of Surrender

Debate over the Japanese Surrender

The debate over what precipitated the Japanese surrender at the end of World War II is a source of contention among historians. This debate has also figured prominently in the discussion of the atomic bombings of Hiroshima and Nagasaki.
The bombing of Hiroshima

Decision to Drop the Bomb

Several committees played key roles in determining how and where the atomic bombs would be dropped on Japan.
The World Set Free

Early Atomic Science

In 1914, novelist H. G. Wells envisioned an atomic bomb that would produce a continual radioactive explosion in his book "The World Set Free."
E. O. Lawrence, A. H. Compton, V. Bush, J. B. Conant, K. Compton, and A. Loomis in March 1940 at UC Berkeley meeting.

Early Government Support - 1939

By late 1939, there was still a lack of an overall "sense of urgency" among other government officials on atomic research.

Effects of Radiation

The first concerted effort to understand and study the effects of radiation on humans began in Chicago in 1942.
Clinch River

Environmental Consequences

Both the Oak Ridge and Hanford sites were chosen for their isolation and access to hydropower from surrounding river systems.
A World War II poster

Espionage

Espionage was one of General Groves' main concerns during the Manhattan Project.
The Dampierre Nuclear Power Plant in northern France

French Atomic Program

France became the fourth country to possess nuclear weapons after its first test in 1960. While development was slowed by the impact of World War II, the achievements of early French research were critical for nuclear development worldwide.
Haigerloch Nuclear Pile

German Atomic Bomb Project

“I don't believe a word of the whole thing,” declared Werner Heisenberg, the scientific head of the German nuclear program, after hearing the news that the United States had dropped an atomic bomb on Hiroshima.

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