McCarthy is a graduate of LeMoyne College, class of 1969 with a BA in history. He then received his MA in American history in 1971. Circumstances led him to a career in government and he received MPA degrees in public finance from the University at Albany and in public management from the Kennedy School of Government at Harvard University. During his long career with New York State he never lost his love of Civil War history, however. As he approached retirement from the position of Assistant Commissioner of the State Department of Transportation, he went back to school and received his Ph.D. in American history from the University at Albany in 2010. His interest in the Battle of Five Forks was kindled during a Capital District Civil War Round Table trip to the battlefield, and this work is a re-edited version of his dissertation.