(the Manhattan Project was a research and development undertaking during ‘World War II’ that produced the first nuclear weapons)
(it was led by the ‘United States’ with the support of the ‘United Kingdom’ and ‘Canada’)
(from 1942 to 1946, the project was under the direction of ‘Major General Leslie Groves’ of the ‘U.S. Army Corps of Engineers’)
(nuclear physicist ‘J. Robert Oppenheimer’ was the director of the ‘Los Alamos Laboratory’ that designed the actual bombs)
(the Army component of the project was designated the Manhattan District; “Manhattan” gradually superseded the official codename, Development of Substitute Materials, for the entire project)
(along the way, the project absorbed its earlier British counterpart, ‘Tube Alloys’)
(the ‘Manhattan Project’ began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US $2 billion (about $27 billion in 2016 dollars))
(over 90% of the cost was for building factories and to produce fissile material, with less than 10% for development and production of the weapons)
(research and production took place at more than 30 sites across the ‘United States’, the ‘United Kingdom’, and ‘Canada’)
(2 types of ‘atomic bombs’ were developed concurrently during the war: a relatively simple gun-type ‘fission weapon’ and a more complex implosion-type ‘nuclear weapon’)
(the ‘Thin Man’ gun-type design proved impractical to use with ‘plutonium’ so a simpler gun-type called ‘Little Boy’ was developed that used ‘uranium-235’, an isotope that makes up only 0.7 percent of natural ‘uranium’)
(chemically identical to the most common ‘isotope’, ‘uranium-238’, and with almost the same mass, it proved difficult to separate the 2)
(3 methods were employed for ‘uranium enrichment’: ‘electromagnetic’, ‘gaseous’, and ‘thermal’)
(most of this work was performed at the ‘Clinton Engineer Works’ at Oak Ridge, ‘Tennessee’)
(in parallel with the work on uranium was an effort to produce ‘plutonium’)
(after the feasibility of the world’s first artificial nuclear reactor was demonstrated in Chicago at the ‘Metallurgical Laboratory’, it designed the ‘X-10 Graphite Reactor’ at ‘Oak Ridge’ and the production reactors in ‘Hanford’, ‘Washington’, in which ‘uranium’ was irradiated and transmuted into ‘plutonium’)
(the ‘plutonium’ was then chemically separated from the ‘uranium’)
(the ‘Fat Man’ implosion-type weapon was developed in a concerted design and development effort by the ‘Los Alamos Laboratory’)
(the project was also charged with gathering intelligence on the German nuclear weapon project)
(through ‘Operation Alsos’, ‘Manhattan Project’ personnel served in ‘Europe’, sometimes behind enemy lines, where they gathered nuclear materials and documents, and rounded up German scientists)
(despite the Manhattan Project’s tight security, Soviet atomic spies still penetrated the program)
(the first nuclear device ever detonated was an implosion-type bomb at the ‘Trinity’ test, conducted at New Mexico’s ‘Alamogordo Bombing and Gunnery Range’ on 16 July 1945)
(‘Little Boy’ and ‘Fat Man’ bombs were used a month later in the atomic bombings of ‘Hiroshima’ and ‘Nagasaki’, respectively)
(in the immediate postwar years, the ‘Manhattan Project’ conducted weapons testing at ‘Bikini Atoll’ as part of ‘Operation Crossroads’, developed new weapons, promoted the development of the network of national laboratories, supported medical research into ‘radiology’ and laid the foundations for the ‘nuclear navy’)
(it maintained control over American atomic weapons research and production until the formation of the ‘United States Atomic Energy Commission’ in January 1947)