Includes correspondence, memoranda, reports, telegrams, newspaper clippings, and printed literature pertaining to Gray's activities in various positions, 1947-1976. Also speech correspondence and some speech transcripts, 1960-1974. Of particular interest are materials relating to Gray's activities as director of the Psychological Strategy Board, 1951-1975; and as chairman, Atomic Energy Commission's Personnel Secruity Board (PSB) investigation of nuclear physicist J. Robert Oppenheimer. The Board met from April 12 to May 6, 1954, investigated and later denied security clearances for Oppenheimer. Materials include correspondence, primarily public opinion letters concerning the case, as well as Gray's dictated memoranda which contain his personal throughts toward the conduct of the case and toward the individuals who testified. Also contained within the corresponde are carbon copies of file memoranda prepared by Roger Robb, counselor for the Atomic Energy Commission. The memoranda which were prepared in 1967 discuss the nature of the case, Oppenheimer as an indiuvidual, and the witnesses at the hearings. Lewis Strauss, chairman of the AEC at the time of the hearings, and Gray maintained an active correspondence up until the 1970s. Much of their correspondence dealt with their involvement in the Oppenheimer proceedings and as such proved interesting insights into the thinking of these two central figures. Also included is an Oppenheimer case scrapbook, compiled on a daily basis by Gray, consisting of newspaper clippings from April to July 1954. The PSB hearing transcripts which were the verbatim account of the proceedings have been withdrawn as they contain unpublished portions which may relate to national security. Other items include: a microfilm copy of scrapbooks documenting Gray's government career, 1946-1950, materials relating to his work as a member of the President's Foreign Intelligence Advisory Board; and documentation of his activities as director of the Psychological Strategy Board (PSB).