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

Secrecy Unveiled - 1945

Henry DeWolf Smyth prepared the official U.S. government history about the development of the atomic bombs.
The Los Alamos main gate

Security and Secrecy

A key component of keeping the Manhattan Project secret was making sure Project sites were secret and secure.
Joe-1 (replica)

Soviet Atomic Program - 1946

Soviet physicists paid close attention to the news of the discovery of fission in Germany in 1938, and began research shortly thereafter.

Soviet Hydrogen Bomb Program

The successful test of RDS-1 in August of 1949 inspired the Soviet government to institute a major, high-priority program to develop the hydrogen bomb.
World War II poster

Special Engineer Detachment

The Army tapped the vast pool of GIs possessing scientific and technical backgrounds, assigning them to the Special Engineer Detachment.
The Nagasaki survey team, including Japanese interpreters and guides

Surveys of Hiroshima and Nagasaki

Manhattan Project members participated in early missions to survey the two atomic bombing sites—Hiroshima and Nagasaki—after the Japanese surrender in August 1945.
Albert Einstein and Leo Szilard working on the famous letter

The Einstein Letter - 1939

In 1939, Albert Einstein sent FDR a letter urging the US conduct research into an atomic bomb.
Fat man.

The Franck Report

Soon after the Interim Committee concluded that the atomic bomb should be used as soon as possible against Japan, a group of scientists led by physicist James Franck founded a committee to study the question of the bomb's use.

The Human Computers of Los Alamos

Before computers became the modern electric desktops or laptops of today, “computers” actually referred to the people who did computing or calculations of equations.