The History of The Atomic Bomb

By lcgarcia

  • Discovery of Nuclear Fission

    Otto Hahn and Fritz Strassman discover nuclear fission in uranium. They learned that the splitting atom releases a huge amount energy.

  • Einstein-Szilard Letter

    Both Leo Szilard and Albert Einstein write a letter to U.S. President Franklin D. Roosevelt, warning them that Nazi German might be developing atomic weapons. Urging the U.S. to begin similiar research.

  • Formation of the Manhattan Project

    Formation of the Manhattan Project- In response to the letter the U.S. establishes the Manhattan Project, a top secret research project about the development of the atom bomb.

  • The First Controlled Nuclear Chain Reaction

    On Dec. 2, 1942 scientists at the University of Chicago achieve the first controlled nuclear chain reaction.

  • Development of the Atomic Bomb

    1943-1945 The Manhattan Project is directed by J. Robert Oppenheimer. During this time the U.S. Government works on the design of the bomb, including both uranium-235 and plutonium-239

  • The Trinity Test

    The first successful test of an atomic bomb takes place in Los Alamos, New Mexico. This marks the first time a nuclear fission weapon is unleashed.

  • Hiroshima

    The U.S. drops the first atomic bomb, "Little Boy" on the Japanese city of Hiroshima killing between 70,000-80,000 people.

  • Nagasaki

    Three days after Hiroshima, the U.S. drops the second atomic bomb, "Fat Man" on Nagasaki killing between 40,000-75,000 people.

  • Japan Surrenders

    Japan surrenders effectively ending World War II. This was after the Hiroshima and Nagasaki bombing.