Leslie Groves died in 1918.
Leslie Groves . 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 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 .