The 8,500 infantry which McClellan had sent to Hooker’s assistance formed the Twelfth Army Corps, commanded by Mansfield; and with those men, too, Jackson’s soldiers were well acquainted.* (* Mansfield’s corps consisted of two divisions, commanded by Crawford (two brigades) and Greene (three brigades). The brigadiers were Knipe, Gordon, Tynedale, Stainbrook, Goodrich.) They were the men who had followed Banks and Shields from Kernstown to Winchester, from Port Republic to Cedar Run; and the Valley army had not yet encountered more determined foes. Their attack was delivered with their wonted vigour. Several regiments, moving west of the turnpike, bore down on the West Wood. But coming into action at considerable intervals, they were roughly handled by Jones’ division, now commanded by Colonel Grigsby, and protected by the rocks; and Stuart’s artillery taking them in flank they were rapidly dispersed. East of the highroad the battle raged with still greater violence. Hood and his Texans, as Lawton’s brigades passed to the rear, dashed across the corn-field against Meade and Ricketts, driving back the infantry on the batteries, and shooting down the gunners. But the Federal line remained unbroken, and Mansfield’s troops were already moving forward. Crawford’s brigade, and then Gordon’s, struck the Texans in front, while Greene, working round the East Wood, made a resolute onslaught on D.H. Hill. The struggle was long and bloody. The men stood like duelists, firing and receiving the fire at fifty or a hundred paces. Crawford lost 1000 men without gaining a foot of ground; but Gordon turned the scale, and Hood’s brigades were gradually forced back through the corn-field to the Dunkard Church. A great gap had now opened in Jackson’s line. Jones’ division, its flank uncovered by Hood’s retreat, found itself compelled to seek a new position. D.H. Hill’s brigades, in the same plight, gave ground towards Sharpsburg; and Greene, following in pursuit, actually crossed the turnpike, and penetrated the West Wood; but neither Hooker nor Mansfield were able to support him, and unassisted he could make no progress.