Manhattan Project

The Manhattan Project was a research and development program led by the United States during World War II to produce the first nuclear weapons, involving collaboration with the United Kingdom and Canada. It employed nearly 130,000 people at its peak and cost approximately $2 billion, with research and production taking place at over 30 sites across the US, UK, and Canada. The project resulted in the development of two types of atomic bombs: a gun-type fission weapon called Little Boy and an implosion-type nuclear weapon called Fat Man, which used uranium-235 and plutonium respectively. The first nuclear device was detonated during the Trinity test on July 16, 1945, followed by the atomic bombings of Hiroshima and Nagasaki a month later, marking the end of World War II.learn more on wikipedia