Kurt Lewin's scientific biography after his 1933 emigration from Nazi Germany and his move to the United States exhibits a complex mix of continuity and change. In his work at the Iowa Child Welfare Research Station between 1935 and1944, Lewin tried to recreate the scientific microculture that had formed around him in Berlin. In the process, he converted biography into theory, adapting to current cultural concerns, to then-prevailing research styles, and to changing institutional and funding networks in American psychology. However, despite their considerable impact at the time, the later reception of Lewin's ideas and methods by American psychologists was ambivalent.