to unite on the Manassas battlefield. Ricketts withdrew via Gainesville to Manassas Junction. Second Bull Run (Manassas) The most significant battle of the campaign, Second Bull Run (Second Manassas), was fought August 28–30. In order to draw Pope's army into battle, Jackson ordered an attack on a Federal column that was passing across his front on the Warrenton Turnpike on August 28, alerting Pope to his position. The fighting at Brawner's Farm lasted several hours and resulted in a stalemate. Pope became convinced that he had trapped Jackson and concentrated the bulk of his army against him. On August 29, Pope launched a series of assaults against Jackson's position along the unfinished railroad grade. The attacks were repulsed with heavy casualties on both sides. At noon, Longstreet arrived on the field from Thoroughfare Gap and took position on Jackson's right flank. On August 30, Pope renewed his attacks, seemingly unaware that Longstreet was on the field. When massed Confederate artillery devastated a Union assault by Porter's 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 driven back to Bull Run. Only an effective Union rearguard action prevented a replay of the First Bull Run disaster. Pope's retreat to Centreville was precipitous, nonetheless. The next day, Lee ordered his army to pursue the retreating Union army. Chantilly Making a wide flanking march, Jackson hoped to cut off the Union retreat from Bull Run. On September 1, beyond Chantilly Plantation on the Little River Turnpike near Ox Hill, Jackson sent his divisions against two Union divisions under Maj. Gens. Philip Kearny and Isaac Stevens. Confederate attacks were stopped by fierce fighting during a severe thunderstorm. Union generals Stevens and Kearny were both killed. Recognizing that his army was still in danger at Fairfax Courthouse, Pope ordered the retreat to continue to Washington. Aftermath The northern Virginia campaign had been expensive for both sides, although Lee's smaller army spent its resources more carefully. Union casualties were 16,054 (1,724 killed, 8,372 wounded, 5,958 missing/captured) out of about 75,000 engaged, roughly comparable to the losses two months earlier in the Seven Days Battles; Confederate losses were 9,197 (1,481 killed, 7,627 wounded, 89 missing/captured) of 48,500. Edward Porter Alexander wrote: ''The [Army of Northern Virginia] acquired that magnificent morale which made them equal to twice their numbers, & which they