After the war , Groves remained in charge of the Manhattan Project until responsibility for nuclear weapons production was handed over to the United States Atomic Energy Commission in 1947 . He then headed the Armed Forces Special Weapons Project , which had been created to control the military aspects of nuclear weapons . He was given a dressing down by the Army Chief of Staff , General of the Army Dwight D. Eisenhower , and told that he would never be appointed Chief of Engineers . Three days later , Groves announced his intention to leave the Army . He was promoted to lieutenant general just before his retirement on 29 February 1948 in recognition of his leadership of the bomb program . By a special Act of Congress , his date of rank was backdated to 16 July 1945 , the date of the Trinity nuclear test . He went on to become a vice-president at Sperry Rand
Trinity nuclear test
Trinity (nuclear test)
Leslie Groves