Timeline of The Manhattan Project - 1942

1942

• January 19: Roosevelt formally authorizes the project.
• January 24: Compton decides to centralize plutonium work at the University of Chicago.
• June 19: S-1 Executive Committee is formed, consisting of Bush, Conant, Compton, Lawrence and Urey.
• June 25: S-1 Executive Committee selects Stone and Webster as primary contractor for construction at the Tennessee site.
• July–September: Physicist Robert Oppenheimer convenes a summer conference at the University of California, Berkeley to discuss the design of a fission bomb. Edward Teller brings up the possibility of a hydrogen bomb as a major point of discussion.
• July 30, Sir John Anderson urges Prime Minister Winston Churchill to pursue a joint project with the United States.
• August 13: The Manhattan Engineering District is established by the Chief of the United States Army Corps of Engineers, Major General Eugene Reybold, effective August 16.
• September 17: Major General Wilhelm D. Styer and Reybold order Colonel Leslie Groves to take over the project.
• September 23: Groves is promoted to brigadier general, and becomes director of the project. The Military Policy Committee, consisting of Bush (with Conant as his alternative), Styer and Rear Admiral William R. Purnell
• September 29: Under Secretary of War Robert P. Patterson authorizes the Corps of Engineers to acquire 56,000 acres (23,000 ha) in Tennessee for Site X, which will become the Oak Ridge, Tennessee, laboratory and production site.
• September 26: The Manhattan Project is given permission to use the highest wartime priority rating by the War Production Board.
• October 19: Groves appoints Oppenheimer to coordinate the scientific research of the project at the Site Y laboratory.
• November 16: Groves and Oppenheimer visit Los Alamos, New Mexico and designate it as the location for Site Y.
• December 2: Chicago Pile-1, the first nuclear reactor goes critical at the University of Chicago under the leadership and design of Enrico Fermi.