The Manhattan Project: The Secret Race to Build the Atomic Bomb

The Manhattan Project was a top-secret American-led research and development program during World War II that produced the first nuclear weapons. At its peak it employed nearly 130,000 people across dozens of sites in the United States, Canada, and the United Kingdom, and it culminated in the atomic bombings of Hiroshima and Nagasaki in August 1945. It remains one of the most consequential scientific and engineering efforts in human history.