On a dark day in April 1865, a band of former Confederate guerillas slaughtered more than forty Comanches, most of them women and children. This began a six-month reign of terror along the Santa Fe Trail as Comanche chief, White Eagle, took his revenge. The U.S. Cavalry was assigned the task of tracking White Eagle and his warriors down. Lieutenant Colonel Ignatius O'Sullivan's orders were to either bring them in or kill them. O'Sullivan, with two...