On June 23, 1944, Thomas Mann became a United States citizen. An excerpt from the article:
"Biographical note on Thomas Mann
Thomas Mann (1875-1955) moved to Switzerland in 1933 shortly after the Nazis had come to power and begun a campaign of abuse against him. He was formally expatriated in 1936. In 1937 the University of Bonn deprived him of his honorary doctorate (restored in 1946), which aroused Mann to a famous and moving reply in which he epitomized the situation of the German writer in exile. Mann, who had anticipated and warned against the rise of fascism during the Weimar Republic (e.g., in Mario and the Magician), continued to combat it in many pamphlets and talks throughout the period of the Nazi regime and the Second World War. He became an American citizen in 1940 [June 23, 1944] and, from 1941 to 1953, lived in Santa Monica, California. After the war he frequently revisited Europe: in 1949 he received the Goethe Prizes of Weimar (East Germany) and Frankfurt (West Germany), but when he finally returned to Europe he settled near Zürich, where he died in 1955.
Among the chief works of Mann’s later years are the novels Lotte in Weimar (1939) [The Beloved Returns], in which the fictional account of a meeting of the lovers of Werther grown old provides the framework for a psychologically and technically ingenious portrait of the old Goethe; Joseph und seine Brüder (1933-43) [Joseph and his Brothers], a version of the Old Testament story which interweaves myth and psychology; and Dr. Faustus (1947), the story of an artist who chooses to pay with self-destruction for the powers of genius, a fate that echoes the last days of the Third Reich; the collections of essays Leiden und Grösse der Meister (1935)[ Suffering and Greatness of the Masters]; and the essay on Schiller, Versuch über Schiller (1955). A complete edition of his works in twelve volumes was published in Berlin (1956) and in Frankfurt (1960)."