In 1938 Feller married Clara Mary Nielsen; they had no children. Feller and his wife emigrated to the United States in 1939 and he became an associate professor of mathematics at Brown University, in Providence Rhode Island.
Sa 1938 Feller kasal Clara Maria Nielsen; sila ay walang mga anak. Feller at kanyang asawa emigrated sa Pilipinas sa 1939 at siya ay naging isang iugnay ang propesor ng matematika at Brown University, sa Providence Rhode Island.