When Nazi Germany absorbed Austria in the Anschluss of 1938, he went to the United States, where he was given a position at the Asia Institute in New York City by Arthur Upham Pope, an eminent authority on Persian art and antiquities who used the institute to help a number of displaced German scholars find work in the United States in the 1930s and 1940s. In 1943, he moved on to the University of Chicago, and was made professor of Arabic in 1949.
When Nazi Germany annexed Austria in the Anschluss of 1938, he went to the United States, where he was appointed a position at the Asia Institute in New York City by Arthur Upham Pope, an eminent expert on Persian art and antiquities who utilized the institute to assist several displaced German scholars find employment in the U.S. during the 1930s and 1940s. In 1943, he relocated to the University of Chicago, where he was appointed professor of Arabic in 1949.