This book is a historical analysis or Brigadier General St. John R. Liddell and his division during the Battle of Chickamauga. Liddell's Division was an ad hoc unit, formed just prior to the battle. During the battle, the unit was involved in five different engagements over a period of three days. These engagements resulted in varying degrees of success and failure. In today's context the performance of the division can be seen as mostly a failure, but from the American Civil War perspective the division's performance in many ways was a success. The division's experiences over the three-day period included: fighting against the overwhelming firepower of a new weapon and suffering numerous casualties; surprising and routing three enemy brigades before being surprised, flanked, and forced to retreat; lacking the will to attack across an open field littered with dead and wounded comrades; attacking and flanking the enemy then being threatened with cut off from the main army; and finally being attacked unexpectedly from the flank and routed. The book begins with a general summation of the battle and an introductory discussion of the structure, leadership, tactics, weapons, and training of the Confederate -v armies during the American Civil War. The book then continues with an examination of General Liddell's life and background before and during the early part of the war. Next, the thesis discusses, as a prelude to Chickamauga, Liddell and his brigades' experiences at the Battle of Stones River and during the Tullahoma Campaign. The thesis continues with a description of the background and combat experiences of the brigade commanders and the units that comprised Liddell's Division. Thereafter, the book analyzes the performance of General Liddell and his division at the Battle of Chickamauga and draws conclusions as to the proximate causes of the performance: causes that are related to the terrain, the organization of the division, the lack of enemy information, and the tactical focus of Liddell and his commanders.