December 1941- Japan bombs Pearl Harbor.
1942- Robert Oppenheimer becomes director of the scientfic efforts of the Manhattan project. The US government secretly begins construction of the atomic bomb.
May 7 1945- Germany agrees to unconditional surrender therefore ending the war in Europe.
July 16, 1945- US successfuly tests the first atomic bomb (code named "Trinity") in New Mexico.
August 6, 1945- The US uses the first atomic bomb as a weapon and drops it on Hiroshima.
August 9, 1945- The second atomic bomb was dropped on Nagasaki.
August 15, 1945- Japan surrenders ending World War Two.