After the early summer collapse of the Union Peninsula Campaign offensive to capture Richmond, Robert E. Lee sought to move his army north and threaten Washington DC before Union forces could regroup. His trusted and highly capable "wing" commanders, Maj. Gens. "Stonewall" Jackson and James Longstreet, brought Lee's army within 35 miles of the Union capital by the end of August. Jackson, who had burned the Federal supply depot at Manassas Junction on August 27th, waited for the arriving Union army just west of the old Bull Run battlefield. Longstreet, trailing Jackson, fought his way eastward through Thoroughfare Gap the next day. In order to draw Maj. Gen. John Pope’s new Union Army of Virginia into battle, Jackson ordered an attack on a Federal column that was passing across his front on the Warrenton Turnpike late on the 28th. The fighting there at Brawner Farm lasted several hours and resulted in a stalemate. Pope became convinced he had trapped Jackson and concentrated the bulk of his army against him. On the 29th, Pope launched a series of assaults against Jackson’s position along an unfinished railroad grade. The attacks were repulsed with heavy casualties on both sides. At noon, Longstreet arrived on the field and took a position on Jackson’s right flank. The afternoon of the 30th, Pope renewed his attacks, seemingly unaware that Longstreet was on the field. When massed Confederate artillery devastated a Union assault by Maj. Gen. Fitz John Porter’s Fifth Corps, Longstreet’s wing of 28,000 men counterattacked in the largest, simultaneous mass assault of the war. The Union left flank was crushed and the army was driven back to Bull Run. Only an effective Union rearguard action prevented a replay of the First Manassas disaster.