He teaches courses on the Civil War, World War II, Vietnam, Americans in combat, and the broad sweep of American military history. A prolific lecturer on military history, he has received numerous awards for outstanding teaching. He has written several books on the American military experience, including "The Deadly Brotherhood: The American Combat Soldier in World War II; The Americans at D-Day;" and, most recently, "Alamo in the Ardennes: The Untold Story of the American Soldiers Who Made the Defense of Bastogne Possible," He is a member of the editorial advisory board at "World War II" magazine and has served as an historical expert for numerous battlefield tours. See less