While Union Gen. Christopher C. Augur's division battled in the cornfield, Union Gen. Alpheus S. Williams launched an attack across an adjacent field then broken by a grove of trees. Jackson's left flank, anchored on a nearby slope, was thinly manned and lacked reserves, and Williams struck it with nearly 1,500 men, crashing through the front line in a furious assault. With Union Gen. Samuel W. Crawford's brigade in the lead, the Federals swept into the exposed Confederate left near the Crittenden Gate. Already bloodied by fighting with Augur's division, the Confederates began to give ground as Jackson's left was crushed and his center threatened. Union Gen. Nathaniel P. Banks thus came to the verge of driving his long-time adversary from the field, though dense trees, hand-to-hand fighting, and the arrival of reinforcements disorganized the Federal assault, and the old Stonewall Brigade slowed but could not stop it.