1964-67 Hunter College, City Universityo of New York
1967-77 The Papers of John Marshall, Institute of Early American History and Culture, College of William and Mary
1977-present University of South Carolina (Columbia); Professor of History and Law, 1977-90; Ernest F. Hollings Professor of Constitutioal Law, 1990-2002; Distinguished Professor of Law Emeritus, 2002-present