1709-1784 1890-1969 18thcentury 1908-1973 1913-1994 1961-1975 20thcentury authors biography english englishliterature history knowledge politicsandgovernment post-traumatic psychologicalaspects psychology psychologyeisenhower psychologyinliterature psychologynixon samuel stressdisorders unitedstates vietnamconflict vietnamwar