This section provides an overview of the history of the Manhattan Project, the key organizations involved, the science behind the bomb, and more.
Manhattan Project members participated in early missions to survey the two atomic bombing sites—Hiroshima and Nagasaki—after the Japanese surrender in August 1945.
In 1939, Albert Einstein sent FDR a letter urging the US conduct research into an atomic bomb.
General Leslie Groves and J. Robert Oppenheimer were a study in contrasts, yet both were key to the Manhattan Project's success.
At 5:29:45 on July 16, 1945, "Gadget" exploded and the Atomic Age began.
On October 30, 1961 the Soviet Union detonated the largest nuclear device in human history. The weapon, nicknamed Tsar Bomba, yielded 57 megatons of TNT, four times larger than any nuclear device tested by the United States.
In the late 1930's and early 1940's, the vast majority of scientific research was conducted at colleges and universities across the US.
By 1938, the confused chemistry of uranium became the "topic of the day" at laboratories everywhere.
The USS Indianapolis was a US Navy cruiser that delivered the components of the Little Boy atomic bomb to Tinian Island. It was later sunk by a Japanese submarine in what became the worst naval disaster in US history.
The US accomplished what other nations thought impossible. How did the United States achieve the remarkable feat of building an atomic bomb?