Jackson’s whole force was four thousand men.  Of the truth of this statement of the respective forces, proof is here given: 

“I have always believed,” said General Sumner afterward, before the war committee, “that, instead of sending these troops into that action in driblets, had General McClellan authorized me to march there forty thousand men on the left flank of the enemy,” etc.

“Hooker formed his corps of eighteen thousand men,” etc., says Mr. Swinton, the able and candid Northern historian of the war.

Jackson’s force is shown by the Confederate official reports.  His corps consisted of Ewell’s division and “Jackson’s old division.”  General Jones, commanding the latter, reported:  “The division at the beginning of the fight numbered not over one thousand six hundred men.”  Early, commanding Ewell’s division,[1] reported the three brigades to number: 

Lawton’s 1,150

Hayes’s 550

Walker’s 700

2,400

“Old Division,” as above 1,600

Jackson’s corps 4,000

[Footnote 1:  After General Lawton was disabled.]

This was the entire force carried by General Jackson into the fight, and these four thousand men, as the reader will perceive, bore the brunt of the first great assault of General McClellan.

Just as the light broadened in the east above the crest of mountains rising in rear of the Federal lines.  General Hooker made his assault.  His aim was plainly to drive the force in his front across the Hagerstown road and back on the Potomac, and in this he seemed about to succeed.  Jackson had placed in front Ewell’s division of twenty-four hundred men.  This force received General Hooker’s charge, and a furious struggle followed, in which the division was nearly destroyed.  A glance at the casualties will show this.  They were remarkable.  General Lawton, division commander, was wounded and carried from the field; Colonel Douglas, brigade commander, was killed; Colonel Walker, also commanding brigade, was disabled; Lawton’s brigade lost five hundred and fifty-four killed and wounded out of eleven hundred and fifty, and five out of six regimental commanders.  Hayes’s brigade lost three hundred and twenty-three out of five hundred and fifty, and all the regimental commanders.  Walker’s brigade lost two hundred and twenty-eight out of less than seven hundred, and three out of four regimental commanders; and, of the staff-officers of the division, scarcely one remained.