 Hull also said that he should have pressed more forcefully for an autopsy to settle lingering doubts about the assassination and demise of the Louisiana political icon.Williams was a Guggenheim Fellow in 1957 and was the Harmsworth Professor of American History at Queen's College of Oxford University in Great Britain from 1966-1967.He was president of the Southern Historical Association from 1958–1959 and of the Organization of American Historians from 1972-1973.