The American Civil War is famous for epic battles involving massive armies outfitted in blue and gray uniforms, details that characterize conventional warfare. A Savage Conflict is the first work to treat guerrilla warfare as critical to understanding the course and outcome of the Civil War. Daniel Sutherland argues that irregular warfare took a large toll on the Confederate war effort by weakening support for state and national governments and diminishing the trust citizens had in their officials to protect them.

Sutherland points out that early in the war Confederate military and political leaders embraced guerrilla tactics. They knew that "partizan" fighters had helped to win the American Revolution. As the war dragged on and defense of the remote spaces of the Confederate territory became more tenuous, guerrilla activity spiraled out of state control. It was adopted by parties who had interests other than Confederate victory, including southern Unionists, violent bands of deserters and draft dodgers, and criminals who saw the war as an opportunity for plunder. Sutherland considers not only the implications such activity had for military strategy but also its effects on people and their attitudes toward the war. Once vital to southern hopes for victory, the guerrilla combatants proved a significant factor in the Confederacy's final collapse.