The Battle of Gettysburg was a scene of roiling chaos. Thousands of casualties and an unexpected Union retreat left the field and its soldiers in utter confusion. It was in the midst of this uproar that Brigadier General Thomas A. Rowley, U.S.A., was arrested for drunkenness and disobedience. But what really happened on that chaotic day, and how did it affect Rowley and those around him in the years to come? A military man for many years, Rowley had served during the Mexican War and had worked his way up from second lieutenant to colonel. When the fighting began at Fort Sumter, he immediately offered his services to the Union Army. This volume chronicles Rowley’s life up to the July 1, 1863, battle that ended his military career, with particular attention to the events of that fateful day. The author discusses the court martial’s questionable guilty verdict and Rowley’s reaction to it, as well as his role in a confrontation between Major General George Meade and G.K. Warren shortly after Lincoln and Stanton reversed the court martial’s finding. Subsequent events in the careers of other participants including Lieutenant Colonel Rufus Dawes and Major General Abner Doubleday are also discussed. Sources include personal letters and diaries of the men who served with and under General Rowley. Pertinent information regarding the military rules of the period is provided in order to reveal how Rowley’s case deviated from the norm. Finally, appendices provide a list of Rowley’s commands, a roll of the court martial participants and Rowley’s personal defense statement.