Final answer:
Doc Boone served for either the Confederate or Union army during the American Civil War, though the information provided does not explicitly state which side he was on.
Step-by-step explanation:
Doc Boone served for the Confederate or Union army during a certain war. Although the provided information does not specify which war or side Doc Boone was a part of directly, it contains references to several conflicts and military forces, including the Army of the Potomac, which was the Union fighting force, and the Confederacy, which was the new nation formed by the secessionist southern states during the American Civil War. The mention of General Robert E. Lee and General George B. McClellan places the setting within the Civil War era. If this question refers to the context provided, Doc Boone's service would likely be during the Civil War for either the Confederate or Union side, depending on which part of the references he is associated with.