-Professor Emeritus, 1994-present, John M. Olin University Professor, 1986-1994, Professorial Lecturer, 1979-1986, Georgetown University

-Faculty, University of Chicago, 1984, 1989; University of Toronto, 1969-1979; Colgate University, 1970; Professor of Government, 1959-1969, Chairman, Department of Government, 1963-1967, Cornell University; Yale University, 1956-1959; Louisiana State University, 1953-1956

-Member, Judicial Fellows Commission, 1986-1988

-Member, National Council on the Humanities, National Endowment for the Humanities, 1982-1988

-Consultant, Task Force on Judicial Selection, Twentieth Century Fund, 1988

-Member, Board of Directors, Institute for Educational Affairs, 1980-1988

-Member, Joint Committee Project ’87, Joint undertaking of the American Historical Association and American Political Science Association to commemorate the bicentennial of the U.S. Constitution, 1987

-Consultant, United States Department of State, 1983-1987

-Lecturer, Phi Beta Kappa Society Lecture Series, 1985-1986

-Member, Council of Scholars, Library of Congress, 1981-1985

-Alternate U.S. Representative, United Nations Commission on Human Rights, 1983

-Guggenheim Fellow, 1978-1979

-Advisory Board Member, National Institute of Law Enforcement, 1974-1976

-Fulbright Fellow; Rockefeller Fellow 1965-1966

-Lecturer, Salzburg Seminar in American Studies, 1959

-Carnegie Teaching Fellow, 1952-1953

- U.S. Navy, 1941-1945

M.A. and Ph.D., University of Chicago

London School of Economics and Political Science

Reed College