Stimson himself, was virtual head of the project and had been during the years of its development as a military weapon. Stimson had conferred frequently with President Roosevelt during this period but his last meeting with FDR had been on March 15th. (See Stimson biography, "On Active Service." Pg. 615). At that time He discussed a memorandum FDR had sent him from an unnamed "distinguished public servant who was fearful lest the Manhattan (atomic) project "be a lemon"; it was an opinion common among those not fully informed....." The writer, alarmed at rumors of extravagance in the project, suggested they get a body of outside scientists to pass on the peject [project] "because rumors are going around that Vannevar Bush and Jim Conant have sold the President a lemon on the subject and ought to be checked up." Stimson characterized it as a "jittery and nervous memorandum and rather silly" and he gave the President a list of scientists actually engaged in it.
Truman's first connection with the bomb project - though he knew nothing of what the project was - occurred long before he became President. It was during his senate service as a member of the appropriations committee and as chairman of the Senate Special Committee to Investigate the National Defense Program - known as the "Truman Committee," when the first appropriation for the project came before the appropriations committee. In talks with the President on at least two occasions (May 5, 1951 and August 6, 1951) he told me of this. He said the appropriation request did not disclose the nature of the project and, as a result, he ordered an investigator for his special committee to look into it. In his memoirs, Truman says that he sent investigators into Tennessee (Oak Ridge) and to the state of Washington (Hanford) to find out what the enormous constructions was and their purpose. Immediately afterward Secretary Stimson called him and they got together. Stimson did not tell him what the project was but did tell him it concerned the topmost secret in the government and that they wanted to go ahead without disclosing any information. On Stimson's assurances, the President called off his investigation and did not go further into the matter. (EAA talk, Aug. 6, 1951). He told me (May 5, 1951) that he knew nothing about the bomb project itself until Stimson went into it with him on April 25, 1945, after he had become president.
On April 12, 1945, after the Cabinet met, soon after he was sworn in at 7:09 p.m., Truman says in his memoirs, that Stimson remained and said he wanted Truman "to know about an immense project that was under way - a project looking to the development of a new explosive of almost unbelievable destructive power." He says this left him puzzled but that "it was the first bit of information that had come to me about the atomic bomb but he gave me no details." He says it was not until the next day that he was told enough to give him some understanding of the developments under way.
April 13, 1945.
President Truman's appointments were:
10:15 - Secretary of State Stettinous
11:00 - Gen. George C. Marshall.
Secretary of War Stimson.
Secretary of Navy Forrestal.
12:30 - To the Capitol for lunch.
2:30 - James F. Byrnes.
The President told me (August 6, 1951) in a long conversation, much of it about the atomic bomb, that it was, he thought, on April 13 that Byrnes, who had been Director of War Mobilization under Roosevelt but had resigned April 2, 1945 and was succeeded by Fred M. Vinson, who had succeeded Byrnes as Head of the Office of Economic Stabilization, and Vinson and told him for the first time something about the project and its purpose. Vinson's name does not appear on the President's appointment list for that day. (Check this).
Byrnes had known of the atomic bomb project for some time but in his book
"Speaking Frankly" (Page 257) he said he did not remember just when Roosevelt told him about it. He believes it was the summer of 1943.
Apr. 12, 1945: After Cabinet met, HST says Stimson remained and told him he wanted Truman "to know about an immense project that was under way - a project looking to the development of a new explosive of almost unbelievable destructive power." HST says it left him puzzled, that "it was the first bit of information that had come to me about the atomic bomb but he gave me no details." He says it was not until the next day that he was told enough to give him some understanding of the developments under way.
Tells also how "many months before, as part of the work of the Committee to Investigate the National Defense Program, of which he was chairman he sent investigators into Tennessee and to the state of Washington to find out what certain enormous constructions were and what their purpose was. Stimson then came to see him and said he could not tell Truman what it was, but it was the greatest project in history of the world and was most top secret. As a result Truman says he called off his investigators.
The next day, Truman writes, James F. Byrnes came to see him and told him a few details - that they were perfecting an explosive great enough to destroy the whole world. (Check Byrnes version in his book).
He says Leahy was with him at the time and that Leahy predicted the bomb never would go off.
Truman also says it was later ÒWhen Vannevar Bush, head of the Office of
Scientific Research and Development came to the White House, that I was given a scientist's version of the atomic bomb. "(Check appointments and date when Bush came to White house) (Also Check Leahy's book and version)."