Donaldson's fiercely candid observations reveal much about the political life of the Army of the Potomac, and his letters contribute unforgettable descriptions of actions at Antietam, Fredericksburg, Chancellorsville, and Gettysburg. Fiercely idealistic in the early days of the war, his letters and diary soon betray a growing disenchantment that leads to a startling climax. 28 photos, 6 maps.