Jackson's weary men took fresh heart; that great commander promptly assumed the offensive, and, advancing his whole line, drove the enemy before him until he reoccupied the ground from which General Sumner had forced him to retire.
From the ground thus occupied, the Federal forces were unable to dislodge him, and the great struggle of "the left at Sharpsburg" was over.

It had begun at dawn and was decided by ten or eleven o'clock, and the troops on both sides had fought as resolutely as in any other action of the war.

The event had been decided by the pertinacity of the Southern troops, and by the prompt movement of reenforcements by General Lee from his right and centre.

Posted near his centre, he had surveyed at one glance the whole field of action; the design of General McClellan to direct his main assault upon the Confederate left was promptly penetrated, and the rapid concentration of the Southern forces in that quarter had, by defeating this movement, decided the result of the battle.
Attacks on the Confederate centre and right followed that upon the left.

In the centre a great disaster was at one time imminent.