William Swinton, Campaigns of the Army of the Potomac

Early in the action, General Keyes, whose troops were those upon whom the attack had thus far fallen, finding he was being hard pushed, had sent to General Heintzelman, who commanded the whole left wing of the army, and whose two divisions were close at hand, to send him aid. But the message was both delayed in reaching that officer,² and when he sent forward re-enforcements, they were, through some misunderstanding, very tardy in reaching the front; so that it was past four o'clock when Kearney, with his foremost brigade,³ arrived at the position where Couch's troops and the wreck of Casey's division were struggling to hold their own.⁴ Berry's brigade was immediately thrown into the woods on the left, where his rifles commanded the left of the camp and works occupied by Casey in the morning, and now held by the enemy.

Meantime, though the divisions of Longstreet and Hill had thus for three hours been vigorously pushing forward on the Williamsburg road, the column of G. W. Smith, to which was intrusted the important flanking operation already indicated in Johnston's original plan, had not yet moved. The Confederate commander had placed himself with this column; but failing to hear the musketry of Longstreet and Hill,⁵ he waited till four o'clock, when, learning how these generals had been engaged, he immediately threw forward Smith's command. Thus it happened that when Casey had been driven back to Couch's line at the Seven Pines, and the latter with two regiments of his division had advanced to relieve the