Though a wide-ranging historian, Koch’s specialty areas are the Civil War and Native American History. He has worked for national historical and natural sites, promoting the nation’s physical and historical heritage. He has also lectured for organizations across the country and in Europe on such topics as Civil War Battles, Politics in the Civil War, Medicine in the Civil War, Abraham Lincoln’s life and political activities, and Slavery and the American Experience, as well as specialized presentations on the Gettysburg National Cemetery, the Battle of Gettysburg, and Connecticut in the Civil War.