In March 1862, 38,000 Union soldiers under Banks advanced into the northern, Shenandoah Valley to prepare to move south to support the planned campaign of Union generalof the Peninsula in an attempt to take Richmond. Confronted by overwhelming numbers, Stonewall Jackson, the Confederate commander in the Valley, withdrew his force south from to Strasburg on March 11, but searched for an opportunity to engage the Union troops. On March 18, Union general Nathaniel P. Banks sent a division under Irish-born general James Shields after Jackson. Failing to engage Jackson, the Union troops retired to Winchester on March 20. Jackson set off after the Union troops on March 22. His cavalry, under Colonel , engaged the Union forces, and in the skirmish an artillery shell wounded Shields. Colonel Nathan Kimball assumed command. Acting on the assumption that his forces outnumbered the Union troops, Jackson pushed his cavalry into taking the offensive against the enemy outside Winchester, near Kernstown, the following day. Jackson, however, had underestimated the Union force; at Kernstown his 3,500 Confederates would fight against 6,352 Union troops. Kimball, likewise, misjudged his enemy; he believed that he faced only Jackson’s cavalry. These distorted understandings of the operational situation led to a confused brawl of a battle.
Jackson’s cavalry under Ashby opened the fight around nine o’clock on the morning of March 23. Kimball initially thought the attack was another cavalry probe, but nonetheless he began to concentrate his forces on Pritchard Hill, an eminence that served as an outstanding defensive position. This prudent move provided Union troops with a strong rallying point, as well as a strong position for their artillery. In an effort to silence the Union guns, Jackson initially deployed artillery, including the, on Sandy Ridge, a second hill to the west of Pritchard Hill. Jackson visited the emplacements at about three thirty and discovered that what he had previously thought to be a Union force of manageable size was instead an entire division. According to , an aide to Jackson at the time, the general looked at the men in blue arrayed against him and remarked, “We are in for it.”
Instead of launching his assault as planned, Jackson concentrated his infantry around his guns on Sandy Ridge, including the, commanded by Brigadier General Richard B. Garnett. Conversely, Kimball, harassed by the fire of the Rockbridge Artillery and believing that Jackson outnumbered his forces, launched an assault on Sandy Ridge in an attempt to silence the offending battery. At four o’clock, his infantry encountered the Stonewall Brigade and sharp fighting broke out. The Confederates enjoyed a strong position, posted behind a stone wall that ran across Sandy Ridge. As the fight wore on, Jackson kept sending in more troops, but he only managed to hold the line.
By four thirty, the situation on Sandy Ridge had stabilized into a stalemate, but Kimball still possessed reserves he could feed into the fight. By six o’clock, the majority of Confederate troops in position behind the stone wall had run out of ammunition and suffered greatly from exhaustion. Observing more Union troops arriving, Garnett gave the order for the Confederates to withdraw while they still might be able to retreat in good order. As Garnett’s men fell back, other Confederate infantry farther down the line also began to retreat. The orderly retreat turned into a pell-mell flight for some Confederates, and nightfall ended the fighting for the day.
Initially, the Union troops pursued Jackson’s retreating men, coming into contact with the rear guard on March 24. Banks rushed to the site of the battle and directed the operations. Despite these early efforts, Banks soon became content to await further developments rather than take a more active role. Jackson, accordingly, withdrew up the Valley and licked his wounds. He also arrested Garnett for his retreat from the stone wall, claiming that Garnett had neglected his duty by withdrawing without orders. Jackson, ever the staunch disciplinarian, could not brook any usurpation of what he perceived as his authority. Jackson’s spurious charges contributed to a decline in morale among the men, especially those of the Stonewall Brigade. Thehad great affection for Garnett and viewed his arrest as unfair. Garnett requested a court-martial to address Jackson’s charges against him. It convened briefly in August, but was suspended due to active campaigning; restored Garnett to duty, and the charges were not resolved before Garnett’s death during at the in July 1863.
On April 3, Banks and his corps received a command independent of the Army of the Potomac, which disrupted McClellan’s plans to march up the Peninsula and on to Richmond. This move created further acrimony between Lincoln and McClellan, and indicated the growing importance the Valley held in Lincoln’s strategic thinking.