After completing his doctoral dissertation on the theory of Superconductivity, Schrieffer spent the 1957–58 academic year as a National Science Foundation fellow at the University of Birmingham in England and at the Niels Bohr Institute in Copenhagen, where he continued research into Superconductivity. Following a year as assistant professor at the University of Chicago, he returned to the University of Illinois in 1959 as a faculty member. In 1960, he went back to the Bohr Institute for a summer visit, during which he became engaged to Anne Grete Thomsen whom he married at Christmas of that year. Two years later, Schrieffer joined the faculty of the University of Pennsylvania in Philadelphia, and, in 1964, Schrieffer published his book on the BCS theory, Theory of Superconductivity. He holds honorary degrees from the Technical University of Munich and the University of Geneva. In 1993 Schrieffer along with Leon Cooper were awarded the Comstock Prize in Physics from the National Academy of Sciences.