General Heintzelman and an unrealized opportunity before Second Bull Run.Here might have been won a Federal victory that would have precluded defeat at Second Bull Run. The corps of General Heintzelman, consisting of the divisions of Hooker and Kearny, was the next detachment of McClellan's forces to arrive to the aid of Pope. On the 28th of August, Heintzelman had pushed forward to Centreville, entering it soon after “Stonewall” Jackson's rear-guard had retired. Instead of pursuing, Heintzelman drew up his forces east of Cub Run, which we see in the picture. Jackson's forces, now in a precarious position, fell back toward Thoroughfare Gap to form a junction with Longstreet's Corps, which Lee had sent forward. The battle was commenced on the west somewhat feebly by Generals McDowell and Sigel. By night-fall the Confederate left had been driven back fully a mile.