Aaron Sheehan-Dean is the Fred C. Frey Chair in Southern Studies and chairman of the Department of History at Louisiana State University. He is the author of the award-winningThe Calculus of Violence: How Americans Fought the Civil War(2018),Why Confederates Fought: Family and Nation in Civil War Virginia (2007), and the Concise Historical Atlas of the U.S. Civil War (2nd ed., 2020). He edited The Cambridge History of the American Civil War and the Companion to the U.S. Civil War, among other books. He has conducted workshops on a variety of topics in U.S. history with elementary, middle, and high school teachers around the country. His more recent book, a comparative study of civil and national conflicts, is Reckoning With Rebellion: War and Sovereignty in the Nineteenth Century.
At least three-quarters of a million lives were lost during the American Civil War. Given its seemingly indiscriminate mass destruction, this conflict is often thought of as the first “total war.” In fact, this notoriously bloody war could have been much worse. Military forces on both sides sought to contain casualties inflicted on soldiers and civilians. In Congress, in church pews, and in letters home, Americans debated the conditions under which lethal violence was legitimate, and their arguments differentiated carefully among victims—women and men, black and white, enslaved and free. Sometimes, these well-meaning restraints led to more carnage by implicitly justifying the killing of people who were not protected by the laws of war. As the Civil War raged on, the Union’s confrontations with guerillas and the Confederacy’s confrontations with black soldiers forced a new reckoning with traditional categories of lawful combatants and raised legal disputes that still hang over military operations around the world today.