The book deals with the efforts of General Irving Morrell's United States Army, having emerged victorious from the Battle of Pittsburgh, to drive Confederate forces out of Ohio. Morrell pursues the Confederates, under General George Patton, across Kentucky and Tennessee (where he easily takes Chattanooga) and into Georgia in a period of about six months. When the book ends, US forces are an established presence in Georgia and are fast coming within range of Atlanta, despite some fearsome new weapons introduced by the Confederates.