The Battle of Cedar Mountain was an American Civil War battle which was fought on 9 August 1862 in Culpeper County, Virginia during John Pope's northern Virginia campaign.
On 26 June 1862, John Pope was given command of the Union Army of Virginia, and he invaded Virginia two months later, hoping that the Confederate defenses of Richmond were still weakened from the Peninsula Campaign. On 13 July, Confederate general Stonewall Jackson was sent to Gordonsville with 14,000 troops, and he was later reinforced with 10,000 troops under A.P. Hill. On 6 August, Pope's army marched into Culpeper County to seize the Gordonsville rail junction and distract the Confederates from George B. McClellan's withdrawal from the Peninsula. Jackson decided to preemptively strike at Pope's vanguard under Nathaniel P. Banks, and Banks took up positions on a ridge above Cedar Run, 7 miles south of Culpeper Court House.
On 9 August 1862, Jackson's army crossed the Rapidan River into Culpeper County, with Richard S. Ewell, Charles Sidney Winder, and A.P. Hill's divisions marching in order. Just before noon, the artillery of Jubal Early's brigade began to clash with Union artillery, and the battle began. The Union forces were able to drive the Confederates from the field early in the battle, but Jackson rallied his troops and had Lawrence O'Bryan Branch lead a counterattack, causing the Union right to collapse, followed by the collapse of the Union left when Isaac R. Trimble's brigade charged down Cedar Mountain. The battle was a Confederate victory, although Winder was mortally wounded by a Union shell. The battle forced Pope to halt his advance in northern Virginia, giving Lee the upper hand in the battles to come.