 He studied mathematics at the University of Chicago and obtained his Ph.D. in 1936 at Brown University under Jacob Tamarkin.He moved in 1939 to Yale University, where he remained until his retirement in 1960.In 1981, he was awarded jointly with Jacob T. Schwartz, his Ph.D. student, the well-known Leroy P. Steele Prize of the American Mathematical Society for the three-volume work "Linear operators".