Hill's command was stationed; two brigades under General Hood were drawn up on Hill's left; and when Jackson arrived Lee directed him to post his command on the left of Hood, his right resting on the Hagerstown road, and his left extending backward obliquely toward the Potomac, here making a large bend, where Stuart with his cavalry and horse-artillery occupied the ground to the river's bank.
This arrangement of his troops was extremely judicious, as the sequel proved.

It was probable that General McClellan would direct his main attack against the Confederate left, with the view of turning that flank and hemming in the Southern army, or driving it into the river.
By retiring Jackson's left, Lee provided for this contingency, and it will be seen that the design attributed by him to his adversary was that determined upon.
General McClellan occupied the ground on the eastern bank of the Antietam.

He had evidently massed his forces opposite the Confederate left, but a heavy order of battle stood opposite the centre and right of Lee, where bridges crossed the stream.
The respective numbers of the adversaries can be stated with accuracy.
"Our forces at the battle of Antietam," said General McClellan, when before the committee of investigation afterward, "were, total in action, eighty-seven thousand one hundred and sixty-four." General Lee says in his report: "This great battle was fought by less than forty thousand men on our side." Colonel Walter H.Taylor, a gentleman of the highest character, and formerly adjutant-general of the army, makes the Confederate numbers somewhat less.

In a memorandum before the writer, he says: Our strength at Sharpsburg.

I think this is correct: Jackson _( including A.P.