The northern Virginia campaign, also known as the second Bull Run campaign or second Manassas campaign, was a series of battles fought in Virginia during August and September 1862 in the Eastern Theater of the American Civil War. Confederate General Robert E. Lee followed up his successes of the Seven Days Battles in the Peninsula campaign by moving north toward Washington, D.C., and defeating Maj. Gen. John Pope and his Army of Virginia. Concerned that Pope's army would combine forces with Maj. Gen. George B. McClellan's Army of the Potomac and overwhelm him, Lee sent Maj. Gen. Thomas J. "Stonewall" Jackson north to intercept Pope's advance toward Gordonsville. The two forces initially clashed at Cedar Mountain on August 9, a Confederate victory. Lee determined that McClellan's army on the Virginia Peninsula was no longer a threat to Richmond and sent most of the rest of his army, Maj. Gen. James Longstreet's command, following Jackson. Jackson conducted a wide-ranging maneuver around Pope's right flank, seizing the large supply depot in Pope's rear, at Manassas Junction, placing his force between Pope and Washington, D.C. Moving to a very defensible position near the battleground of the 1861 First Battle of Bull Run (First Manassas), Jackson successfully repulsed Union assaults on August 29 as Lee and Longstreet's command arrived on the battlefield. On August 30, Pope attacked again, but was surprised to be caught between attacks by Longstreet and Jackson, and was forced to withdraw with heavy losses. The campaign concluded with another flanking maneuver by Jackson, which Pope engaged at the Battle of Chantilly on September 1. Lee's maneuvering of the Army of Northern Virginia against Pope is considered a military masterpiece. Historian John J. Hennessy wrote that "Lee may have fought cleverer battles, but this was his greatest campaign." Background Military situation After the collapse of McClellan's Peninsula campaign in the Seven Days Battles of June, President Abraham Lincoln appointed John Pope to command the newly formed Army of Virginia. Pope had achieved some success in the Western Theater, and Lincoln sought a more aggressive general than McClellan. Pope did not endear himself to his subordinate commanders—all three selected as corps commanders technically outranked him—or to his junior officers, by his boastful orders that implied Eastern soldiers were inferior to their Western counterparts. Some of his enlisted men were encouraged by Pope's aggressive tone. The Union Army of Virginia was constituted on