Henry DeWolf Smyth is perhaps best known for authoring the "Smyth Report," the official government report on the development of the atomic bomb. His diaries offer a glimpse into that report, as well as his career as physicist, diplomat, instructor, policy maker, and administrator. Recorded in 37 notebooks spanning 35 years (1935-1970), the Smyth appointment books reveal his research, extensive professional networks, and wide-ranging travels through the records of meetings, travel arrangements, cocktail parties, and dinners that filled his schedule. While the first couple journals are maintained in small "Lest We Forget" notebooks (1935-1936), the bulk of the collection is available in larger "Frances Juvenile Home Calendar Club" (1936-1958) and "Engagements" books (1959-1970) packed with notes, lists, asides, and occasional newspaper clippings. Notably, he pastes newspaper clippings related to World War II at the front of contemporaneous diaries (1939-1945) and interweaves key news from the war into his own record-keeping, including the attack on Pearl Harbor and U.S. declaration of war (12/7-12/9/1941), the death of President Roosevelt (4/12/1945), and the deployment of both atomic bombs in Hiroshima and Nagasaki (8/6-8/9/1941). Although the notes are spare, nested within them are insinuations of Smyth's ascendant career. For example, one note records his appointment as Commissioner of the U.S. Atomic Energy Commission: "Pres. Truman sees H.— [Henry] offers commission house job. H. home for dinner. We decide yes" (4/18/1949). While it is unclear who authors all of the earlier entries, his wife, Mary C. Smyth, clearly maintains later "Engagements" books (1959-1970). Notably, the "Gray Board" hearings are also detailed in separate page associated with her 1954 diary. Thus, these volumes ought to interest scholars researching Smyth's role in atomic history and international diplomacy as well as those seeking to elevate figures—such as Mary C. Smyth—whose labor might otherwise remain invisible.