This section provides an overview of the history of the Manhattan Project, the key organizations involved, the science behind the bomb, and more.
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 official logo of the Strategic Defense Initiative

Strategic Defense Initiative (SDI)

During the 1980s, President Ronald Reagan initiated the Strategic Defense Initiative (SDI), otherwise known as "Star Wars," an anti-ballistic missile program that was designed to shoot down nuclear missiles in space.
Manhattan Project Survey Team in Hiroshima. Photo courtesy of the Patricia Cox Owen Collection, AHF.

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.
The Hiroshima Atomic Dome, the only building left standing near the epicenter of the bombing.

Survivors of Hiroshima and Nagasaki

By the end of 1945, the atomic bombings of Japan had killed an estimated 140,000 people at Hiroshima and 74,000 at Nagasaki. Often lost in those numbers are the experiences of the survivors, known as the hibakusha.
The Berlin Wall

The Berlin Wall

Soviet leader Nikita Khrushchev decided that the time had come to erect a wall between the eastern and western portions of Berlin. In 1961, preliminary construction of the Berlin Wall began.
Albert Einstein and Leo Szilard working on the famous letter

The Einstein-Szilard 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.
Japanese Relocation Notice

The Incarceration of Japanese-Americans during World War II

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.