The atomic bombing of Japan in early August 1945 suddenly thrust the Manhattan Project into the center of the public eye. What formerly had been privy to a select few now became the object of intense public curiosity and scrutiny. Manhattan Project officials, however, had no intent to release what they viewed as essential military secrets. To both allay inordinate inquisitiveness and satisfy the legitimate public need to know, officials in early 1944 began a carefully designed public relations program in anticipation of when they would have to announce the news to the world. They perceived that, from the standpoint of security, the release of some selected information would make it easier to maintain the secrecy of the highly classified aspects of the project. The public relations program had two parts: preparation of a series of public releases and preparation of an administrative and scientific history of the project. The press releases related to the Tolman Report activities can be found in the previously released "Manhattan Project Resources" Spotlight in the Manhattan District History books. Specifically, Book I General, Volume 4 Auxiliary Activities, Chapter 8 – Press Releases - Part 1, PDF pages 97 and 297-299."
Major General Leslie R. Groves, director of the Manhattan Engineer District (MED), commissioned Henry DeWolf Smyth, a Princeton physicist and a consultant to the Manhattan Project, to prepare the administrative and scientific history. On August 12, 1945, three days after the Nagasaki bombing, the War Department released A General Account of the Development of Methods of Using Atomic Energy for Military Purposes, which became known as the Smyth Report. The report contained a wealth of information lucidly presented, but, as Groves clearly stated in his foreword, "no requests for additional information should be made." Persons either disclosing or securing additional information without authorization, Groves declared, would be "subject to severe penalties under the Espionage Act." This report has been posted previously on OpenNet, and may be found here.
Scientists involved with the project, nonetheless, advocated for more openness and freedom of research, and project contractors pushed for the Army to declassify reports relating to their wartime work. As a result, Groves in early November 1945 asked Richard C. Tolman, a Caltech chemist and scientific adviser to Groves, to draft a declassification policy. Tolman assembled a committee composed of Robert Bacher, Ernest O. Lawrence, J. Robert Oppenheimer, Frank Spedding, Harold Urey, and John Ruhoff. Although the committee was not convinced that concealing scientific information could long contribute to national security, it seemed inevitable that there would continue to be classification in some areas. Using a topical list of production and research activities in the Manhattan Project, the committee assigned each subject to one of three categories: information recommended for immediate declassification, information whose declassification would be conducive to the national welfare and to long-term national security, and that not recommended for declassification. The committee suggested that the list serve as a temporary declassification guide. Tolman proposed a procedure whereby directors of laboratories and other organizations would select documents for declassification and submit them to one of several Responsible Reviewers, according to subject matter. The Reviewers would recommend action by the Manhattan district declassification office after checking the documents against the guide and the Army patent regulations. The committee provided an initial report to Groves on November 17, 1945, with follow up reports in February and June 1946 after conferring with and receiving input from the major Manhattan Project contractors.
Groves responded favorably to the report, and he cleared the committee's proposal with President Harry Truman in early March 1946. The first four formal declassification guides were prepared and released by the end of March 1946, and an organizational structure to implement the declassification guidance was in place by the end of July. Groves appointed four Senior Responsible Reviewers: Warren C. Johnson for the pile project, Willard F. Libby for gaseous diffusion, Robert L. Thornton for electromagnetic separation, and John H. Manley for weapons. Before the end of 1946, the committee of reviewers held three meetings and declassified about 500 documents. Although many scientists outside the project dismissed this output as insignificant, the reviewers had devoted considerable effort to studying the variety of complex technical categories and preparing detailed guides. However minimal the initial results, the Atomic Energy Commission, which took over most of the MED's responsibilities and physical assets on January 1, 1947, inherited a carefully conceived, well organized administrative procedure.
Following is a listing of the Tolman Committee Reports with links to PDF copies: