In June 1942, the U.S. Army established the Manhattan Engineer District to handle its part in the atom bomb project, beginning the process of transferring responsibility from the Office of Scientific Research and Development to the military. In September, Brigadier General Leslie R. Groves Jr., was appointed director of what became known as the Manhattan Project. By October 12, 1942, Groves and Oppenheimer had decided that for security and cohesion, they needed to establish a centralized, secret research laboratory in a remote location.