Best known as author of the "Smyth Report," the official government report on the development of the atomic bomb, Henry DeWolf Smyth had a long and varied career as a physicist, diplomat, instructor, policy maker, and administrator. Taking leave from his position with the Physics Department at Princeton, Smyth began work on the Uranium committee of the National Defense Research Committee in 1940, serving as a consultant on the Manhattan Project from 1943-1945. Although he returned to Princeton after the war, Smyth left academia to become Commissioner of the U.S. Atomic Energy Commission (AEC) from 1949 to 1954, and he subsequently served as U.S. Representative to the International Atomic Energy Agency (IAEA), from 1961 to 1970. The Smyth Papers (1885-1987) contain correspondence, subject files, speeches, manuscripts of unpublished and published works, reprints and printed publications, scientific class notes and papers, newspaper clippings, photographs, and memorabilia which document Smyth's career as a physicist and statesman. The bulk of the collection dates from approximately 1944 to 1970, the most active and influential years of his career, providing good documentation of his work on the Manhattan Project and the Smyth Report, and his involvement with the U.S. Atomic Energy Commission and the International Atomic Energy Commission.