This book constitutes an operational study of the Army of the Potomac during this campaign and battle, carefully documenting the command decisions of army commander George B. McClellan and following the execution of those decisions through the corps level of command and down to the ordinary soldier in the Second Army Corps. It reappraises the leadership and decisions of Edwin V. Sumner during the battle of Antietam as the one federal corps commander who was steadfast in carrying out McClellan's plan of battle and effectively directed the battle on the Federal right.In Civil War history, the commander's intent is generally treated as a cartoon thought bubble inked over the head of a caricature.
This is going to set an uncomfortable precedent for the innumerable generalizers and synthesizers.