Eventually, the Manhattan Project employed more than 130,000 people and cost nearly US$ 2 billion (equivalent to US$ 23 billion in 2007 dollars). It created multiple secret production and research sites, the three primary ones being: the plutonium-production facility at what is now the Hanford Site (Washington state); uranium-enrichment facilities at Oak Ridge, Tennessee; and the weapons research and design laboratory, now known as Los Alamos National Laboratory in New Mexico. Project research took place at over 30 different sites across the United States, Canada and the United Kingdom. The Manhattan Project maintained control over United States’ weapons production until formation of the US Atomic Energy Commission in January 1947.
Josef Rotblat left the Manhattan Project after Nazi-Germany surrendered in May 1945.
One noteworthy “defection” from the Manhattan Project was that of Polish-born scientist, Josef Rotblat, who protested the completion of the Manhattan project after it had become clear that a nuclear programme did not exist in Nazi-Germany. He left for moral reasons after Germany surrendered in May 1945. He was one of the nine scientists to sign the Russell-Einstein Manifesto. He also helped to found, and later became President of, the annual Pugwash Conferences on Science and World Affairs and received the Nobel Peace Prize in 1995.