He is a retired army officer who also taught U.S. history at West Point. Dr. Snell is the author or editor of four books, the most recent of which is Unknown Soldiers: The American Expeditionary Forces in Memory and Remembrance (Kent, Ohio: Kent State University Press, 2008). He holds a Ph.D. in history and public administration from the University of Missouri, Kansas City.In 2008 he was the visiting senior lecturer of War Studies at the Royal Military Academy, Sandhurst.