Thomas B. Mack (Ph.D.), is the author of the book The Lead Mine Men: The Enduring 45th Illinois Volunteer Infantry, which delves into the ordeals and triumphs of the Midwestern regiment that boasted the lowest rate of desertion during the American Civil War. Mack is the owner and program manager of 1990 Consulting, and he taught U.S. history at Dallas College El Centro Campus.