The John Slater Papers include abstracts from his diaries, available as loose, mostly typed pages, which traverse his consequential career in physics (1900-1975). These abstracts trace Slater's doctoral study at Harvard (1923) and postgraduate work at Cambridge University, appointment at MIT (1930), work at the Laboratory for Nuclear Science during World War II, and late-career at the University of Florida (after his retirement from MIT in 1966). His diaries contain notes about a trip to Japan (including Hiroshima and Nagasaki) in the fall 1953, meetings with defense contractors (such as Lockheed Martin) throughout the 1950s and 1960s, a sighting of Sputnik (7/20/1958), notes about an "NSF proposal for computing center" (4/30/1965), associations with and publications of APS members (7/7/1951, 7/7/1972), and Slater's own personal affairs, as excerpted in Selected Quotations. As such, these abstracts may interest scholars researching John Clark Slater's career in the field of physics, biochemistry, atomic history, and the history of science more broadly, as well as those considering World War II and military contractors in the Cold War period, the space race, the history of computing, and the institutional history of the American Philosophical Society.; To supplement these diary abstracts, researchers might choose to expand their exploration of the Slater Papers, which also contain 133 research notebooks (1944-1976), a lengthy series of folders, containing lectures, scientific notes, drafts of manuscripts and papers, correspondence from his collaboration with the Los Alamos Labs (1966-1970), and correspondence relating to the National Academy of Science.