Facilities for the research were set up in Manhattan, Washington State, Tennessee, and New Mexico. Groves oversaw the military’s participation, while civilian scientist Robert Oppenheimer was in charge of the team designing the core details of Little Boy. Scientists developed the technology for the atomic weapon during the highly classified project code-named “The Manhattan Project.” U.S. In an instant when the first bomb was dropped, tens of thousands of residents of Hiroshima, Japan were killed by “Little Boy,” the code name for the first atomic bomb used in warfare in world history. Two American atomic bombs ended World War II in August 1945, and the devastation will be forever remembered. Hancock, an archives technician at the National Archives at College Park, MD. August 6, 2020, marks the 75th anniversary of the dropping of the first atomic bomb.
