The New York Times and the New York Herald Tribune were examined for each day of the period studied. Supplementary material and additional insights were drawn from other major dailies and a multitude of local papers representing all parts of the country. At the British Museum the files of the Times of London and the Daily Express were helpful for an appraisal of English sentiment. Further information was obtained by scrutinizing such magazines as Time and Newsweek, as well as The Nation, The New Republic and other journals of opinion. Such partisan publications as The Republican contained helpful material.
A publication of the United States Department of State, Documents on German Foreign Policy, Series D, Volume X ( Washington, D.C., 1949), exposes the correspondence between Hans Thomsen and the German Foreign Office. Closely related to this topic, two recent books have also clarified the extent of German activity in the United States during 1940. They are: Alton Frye, Nazi Germany and the American Hemisphere, 1933-1941 ( New Haven, Connecticut: Yale University Press, 1967), and James V. Compton, The Swastika and the Eagle ( Boston: Houghton Mifflin Company, 1967).
A helpful contemporary investigation of Nazi sympathizers in America is John Roy Carlson Undercover ( Philadelphia: The Blakiston Company, 1943). For an intelligent reconsideration of an intriguing subject see Manfred Jonas, Isolationism in America, 1935- 1941 ( Ithaca, New York: Cornell University Press, 1966). Also