Pepper never again sought political office, although many thought he wanted a seat on the Supreme Court. He continued as a Republican National Committeeman until 1928, then remained politically active and served on the platform committees at the 1940 and 1948 Republican National Conventions. He participated in a committee that attempted to make Philadelphia the headquarters of the United Nations in 1946, and continued his efforts to promote Christian unity. Pepper also continued as a trustee of the University of Pennsylvania and of the Carnegie Foundation for the rest of his life.