He was involved in most aspects of the atomic bomb's development: he participated in the selection of sites for research and production at Oak Ridge, Tennessee; Los Alamos, New Mexico; and Hanford, Washington.

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.

[4] Leslie Groves Sr. resigned as pastor of the Sixth Presbyterian church in Albany in December 1896 to become a United States Army chaplain.

While completing high school, he enrolled in courses at the University of Washington, in anticipation of attempting to gain an appointment to the United States Military Academy.

He earned a nomination from the President, Woodrow Wilson, which allowed him to compete for a vacancy, but did not score a high enough mark on the examination to be admitted.

Groves finished fourth in his class, which earned him a commission as a second lieutenant in the Corps of Engineers, the first choice of most high ranking cadets.

[10][11] At MIT he had played tennis informally, but at West Point he could not skate for ice hockey, did not like basketball, and was not good enough for baseball or track.

Following the 1931 Nicaragua earthquake, Groves took over responsibility for Managua's water supply system, for which he was awarded the Nicaraguan Presidential Medal of Merit.

In attendance were Captain Clarence Renshaw, one of Groves's assistants; Major Hugh J. Casey, the chief of the Construction Division's Design and Engineering Section; and George Bergstrom, a former president of the American Institute of Architects.

Casey and Bergstrom had designed an enormous office complex to house the War Department's 40,000 staff together in one building, a five-story, five-sided structure, which would ultimately become the Pentagon.

[33] Meanwhile, Groves had met with J. Robert Oppenheimer, a physicist at the University of California, Berkeley, and discussed the creation of a laboratory where the bomb could be designed and tested.

These were features that Groves found lacking in other scientists, and he knew that broad knowledge would be vital in an interdisciplinary project that would involve not just physics, but chemistry, metallurgy, ordnance, and engineering.

Unlike Oak Ridge, the ranch school at Los Alamos, along with 54,000 acres (22,000 ha) of surrounding forest and grazing land, was soon acquired.

[41] Groves went to Donald M. Nelson, the chairman of the War Production Board and, after threatening to take the matter to the President, obtained a AAA priority for the Manhattan project.

In order to avoid briefing the Treasury Secretary, Henry Morgenthau Jr., on the project, a special account not subject to the usual auditing and controls was used to hold Trust monies.

[43] Worried by the heavy losses occurring during the Battle of the Bulge, in late December 1944 President Roosevelt requested atomic bombs be dropped on Germany during his only meeting with Groves during the war.

Groves created Operation Alsos, special intelligence teams that would follow in the wake of the advancing armies, rounding up enemy scientists and collecting what technical information and technology they could.

The Manhattan District organized its own counterintelligence which gradually grew in size and scope,[46] but strict security measures failed to prevent the Soviets from conducting a successful espionage program that stole some of its most important secrets.

[47] Groves met with General Henry H. Arnold, the Chief of U.S. Army Air Forces, in March 1944 to discuss the delivery of the finished bombs to their targets.

[50] At this point, Secretary of War Henry L. Stimson intervened, announcing that he would be making the targeting decision, and that he would not authorize the bombing of Kyoto.

His was the responsibility for procuring materiel and personnel, marshalling the forces of government and industry, erecting huge plants, blending the scientific efforts of the United States and foreign countries, and maintaining completely secret the search for a key to release atomic energy.

He accomplished his task with such outstanding success that in an amazingly short time the Manhattan Engineer District solved this problem of staggering complexity, defeating the Axis powers in the race to produce an instrument whose peacetime potentialities are no less marvellous than its wartime application is awesome.

[52]Groves had previously been nominated for the Distinguished Service Medal for his work on the Pentagon, but to avoid drawing attention to the Manhattan Project, it had not been awarded at the time.

Eisenhower recounted a long list of complaints about Groves pertaining to his rudeness, arrogance, insensitivity, contempt for the rules, and maneuvering for promotion out of turn.

[55] Groves realized that in the rapidly shrinking postwar military he would not be given any assignment similar in importance to the one he had held in the Manhattan Project, as such posts would go to combat commanders returning from overseas, and he decided to leave the Army.

[55] In recognition of his leadership of the Manhattan Project, he received an honorary promotion to lieutenant general by special Act of Congress,[56] effective 24 January 1948, just before his retirement on 29 February 1948.

[58] In 1964, he moved back to Washington, D.C.[59] Groves suffered a heart attack[60] caused by chronic calcification of the aortic valve on 13 July 1970.

[61][62] A funeral service was held in the chapel at Fort Myer, Virginia, after which Groves was interred in Arlington National Cemetery next to his brother Allen, who had died of pneumonia in 1916.

The same year, he was played by Richard Herd in the American television movie, Enola Gay: The Men, the Mission, the Atomic Bomb.

In the 1989 film Fat Man and Little Boy, he was portrayed by Paul Newman,[66] and in the made-for-TV movie of the same year, Day One, by Brian Dennehy.