I learned it from Clausewitz, On War.

Here’s an edit : NYG, how would you assess the tactical outcome of the Battle of Malvern Hill , 78 days before Antietam?
The AOP abandoned the field, and yielded the strategic victory to the South. No doubt there. But who got the better of the fighting that day ? A sharp rebel defeat, I’d say. Would you credit Lee with tactical victory at the Battle of Malvern Hill ?

Regards, Phil

McClellan spends almost the whole battle at the Pry House. He climbs to the attic, stands on a barrel and observes through a trap door. He also crosses the yard to an observation telescope and looks across the Antietam. He only once crosses the creek to the west to personally take part in the action, and that limited to meeting Franklin. Franklin, normally as cautious as little Mac, pleads with McClellan to sen in his entire corps. Sumner, who exercises virtually no command and control over his disjointed attacks and movements, becomes undone over what has happened to Sedgwick and his men, and advises McClellan not to accede to Franklin.

Lee is all over the field checking and directly informing himself of his lines. At 10:00 he is even near the Dunker Church and doesn`t recognize a dirty gunner who must inform him he is his own son. He is virtually all over the field , along his line. He holds the field against almost double his number, then holds the field the next day inviting attack.

Yet we are to declare McClellan the tactical victor? In my opinion, that is not reality. I am entitled to that opinion. Many other historians agree with me. Many other don`t. But my calling Antietam a battle draw, and a strategic victory for the north is, in my entitled opinion....a realistic statement.

Respects, Morris

Sure....he made a truce to collect wounded off of the battlefield.

If he was that desperate, he could have attacked the top.

There wasn't much that medicine could offer.
99.8% of those with penetrating head wounds died.
67% of those shot in the chest, died.
87% of those shot in the abdomen died.
75% of those shot in the extremities, survived. And they underwent an amputation.

One of the reflections I have made upon Antietam was this: The center of the Confederate line along the sunken lane was a fairly strong position from which to defend. But when Barlow`s 61st and 64th New York were advanced to a position from which they could enfilade the sunken road on the right of the line, the bodies started to pile up in the lane. Was this the cause, upon evaluation and after-action reports, of Longstreet`s insistence going forward on traverses in his prepared lines. We know that he was once again to use a sunken lane to great advantage at Fredericksburg. We also know that he continued to improve the position he held in the weeks after the battle there. In January,( I believe) Lee was called to Richmond for consultations with Davis. During this time frame, Longstreet invited Jackson to tour and inspect Longstreet`s improvements. Jackson was impressed with the extensive fortifications, a network of entrenchments and traverses....impressed enough to order more work to improve his own lines.
And did this add further confidence, in May, to Lee that 10,000 could hold the positions long enough against Sedgwick that he could move on Hooker at Chancellorsville and gain the time needed to meet that threat?

Respects, Morris