1944 The director of the Manhattan Project, Maj. Gen. Leslie R. Groves, Jr., commissioned an official US government history and statement about the development of the bombs and the basic physics involved. It was a statement also to other scientists about what information had been declassified. It informed policy-making by giving the general public enough information to understand the new weapons. The book described the development of previously secret labs and production sites. The book did not treat chemistry, metallurgy, and ordnance.
1944 Henry Smyth raised the idea of a public unclassified report about the Manhattan Project. His Princeton department director took the idea to Harvard President, who had had the same idea, and who took it to Groves, who wrote Smyth a letter asking him to write such a report. The work and author were approved May 1944 by the Military Policy Committee. Groves provided guards, military couriers, and secretaries for Smyth's Princeton office, barred his windows, approved his research assistant, gave him security clearance to tour and interview the Project, and sent out letters to the senior managers explaining the Smyth's purpose.
In reviewing the draft, Groves' criticisms included that it was too technical, didn't sufficiently mention participants deserving (which he felt would lessen dangers of security breaches. Chemists and metallurgists did write complaints to Smyth for being left out). The revised draft was reviewed and censored by a scientific adviser and his two aids. Grove obtained permission from the British and US governments (the Allies involved in the Project). After a private 1000-run printing was made, final approval was given by Truman 3 days after Hiroshima. The immediate release was authorized and the War Department released the 1000 copies.
Summer 1945 Smyth approached Princeton University Press' director about printing 5000 copies of a top secret report, which the director chose not to risk. After the report was officially released, the director offered to publish it, but Smyth pursued McGraw-Hill. McGraw-Hill found it boring and unprofitable, so Smyth turned back to Princeton University Press, on the condition Smyth receive no royalties. Princeton University Press's condition was Grove's approval, obtained August 25 by letter.
1945 Oct. until 1946 Jan. the Smyth Report was on the NY Times best-seller list, and although booksellers had been initially wary of the technical volume, it sold 127 000 copies in its first 8 printings.
Changes were made to the text early on. Names were given instead of abbreviations, details about the height of atomic detonation reducing fallout were given, a not about the poison effect of fission products in production reactors was removed. A 40-page report from the British government detailing its own involvement in the project was included in the 5th printing, and a 2-page Canadian report was added in a later printing.
There was concern the report would give away secrets to the USSR.
The Soviet program used the report as a blueprint, copying American procedures, including the use of "secret cities" that disappeared from maps.
The ultimate responsibility for our nation's policy rests on its citizens and they can discharge such responsibilities wisely only if they are informed. The average citizen cannot be expected to understand clearly how an atomic bomb is constructed or how it works but there is in this country a substantial group of engineers and scientists who can understand such things and who can explain the potentialities of atomic bombs to their fellow citizens. The present report is written for this professional group and is a matter-of-fact, general account of work in the USA since 1939 aimed at the production of such bombs. It is neither a documented official history nor a technical treatise for experts. Secrecy requirements have affected both the detailed content and general emphasis so that many interesting developments have been omitted.
All pertinent scientific information which can be released to the public at this time without violating the needs of national security is contained in this volume. No requests for additional information should be made to private persons or organizations associated directly or indirectly with the project. Persons disclosing or securing additional information by any means whatsoever without authorization are subject to severe penalties under the Espionage Act.