In 1955 , Manchester became an editor for Wesleyan University and the Wesleyan University Press and spent the rest of his career at the university . For the academic year 1959 – 1960 , he was a Fellow on the faculty at the Center for Advanced Studies of Wesleyan . He later became an adjunct professor of history , adjunct professor emeritus , and writer-in-residence at the university . During his association with Wesleyan University , Manchester developed an intense writing regimen that he adhered to for much of his life , often writing nonstop for up to 50 hours at a time . He described the experience as follows : " I would work all day , all night , all the next day , all the following night and into the third day . I would look up at the clock , and it would be 3:30 in the afternoon , and I would say , ' Oh boy , I 've got three more hours to write . ' I just loved it . " His best-selling book , '' The Death of a President '' ( 1967 ) , is a detailed account of the assassination of President John F. Kennedy , who had been the subject of an earlier book by Manchester . In 1964 , Manchester was commissioned by the Kennedy family to write the book . Manchester , who retraced the movements of President Kennedy and Lee Harvey Oswald before the assassination , concluded , based on his study of Oswald 's psychology and their similar training as Marine sharpshooters , that Oswald had acted alone . Manchester had the support of Robert and Jacqueline Kennedy , but later had a falling-out with Robert over Manchester 's treatment of President Lyndon B. Johnson
assassination of President John F. Kennedy
Assassination of John F. Kennedy
William Manchester