Professor Seamon joined the University of Idaho in 2004, having previously taught at the University of South Carolina School of Law and Washington and Lee Law School. He currently teaches Administrative Law and Constitutional Law, and serves as Interim Associate Dean for Faculty Affairs.  In the past, he has taught courses on civil procedure, criminal procedure, federal courts, and U.S. Supreme Court practice. He also served as the associate dean for administration and students from 2006–2009. 

Before he became a law professor, Professor Seamon practiced law for ten years. In 1986, he clerked for Kenneth W. Starr on the U.S. Court of Appeals for the District of Columbia Circuit.  From 1987–1990, he worked as an associate at the Washington, D.C. law firm Covington & Burling.  From 1990–1996, he served in the U.S. Department of Justice as an assistant to the Solicitor General of the United States. While at the Justice Department, Professor Seamon presented oral argument before the U.S. Supreme Court in fifteen cases.  He became a law professor in 1996.

Professor Seamon has written or co-authored four books, the most recent of which are: The Supreme Court Sourcebook (Wolters Kluwer 2013) (co-authored with A. Siegel, J. Thai, and K. Watts); Administrative Law: A Context and Practice Casebook (Carolina Academic Press 2013); and Administrative Law: Examples and Explanations (Wolters Kluwer 4th ed., 2012) (co-authored with W. Funk). Professor Seamon has also written many law review articles on constitutional law and other public law subjects. 

Professor Seamon received his J.D. from Duke Law School and holds a B.A. and an M.A. from Johns Hopkins University. He graduated from law school as a member of Order of the Coif and from college as a member of Phi Beta Kappa. He is also an elected member of the American Law Institute.