Every leader needs a trusted confidant. For Nathan Bedford Forrest, one of the Civil War's greatest military minds, that man was David Campbell Kelley. Kelley began adulthood in the clergy, serving for two years as a missionary in China and returning home just a year before the Civil War. He then raised a company of cavalry from his family's large congregation that became part of Forrest's original regiment. Kelley quickly became Forrest's second in command, assisting in some of his most daring engagements, offering support in key decisions and serving as his unofficial chaplain. Following...