From the hills and valleys of Appalachia to the sun-drenched plains of Missouri and “bleeding” Kansas, a violent clandestine war was waged far from the famous Civil War battlefields that saw tens of thousands fall in line of battle. Bands of irregular Rebel cavalry fought a hit-and-run warfare against Union troops and the pro-Union population.Despite the brutality of their guerrilla tactics, there were constraints—women and were children were usually left with a roof over their heads. But along the Kansas-Missouri border a crueler war was fought by both sides in which no quarter given. Of the thousands of partisans involved, John Singleton Mosby, William Clarke Quantrill and William T. “Bloody Bill” Anderson became famous for their savagery.