The Manhattan Project
The Manhattan Project was a secret Word War II U.S. weapons program, created in 1942 in response to fears that Nazi Germany was close to building a nuclear weapon. The Project, led by Dr. Robert Oppenheimer, employed some of the best scientists of the era. In 1945, these scientists succeeded in building four nuclear weapons, two of which were dropped on the Japanese cities of Hiroshima and Nagasaki. This controversial attack ended World War II and set the stage for the Cold War.