Maj. Gen. Nathaniel P. Banks learned on May 24, 1862, that the Confederates had captured his garrison at Front Royal, Virginia, and were closing on Winchester, turning his position. He ordered a hasty retreat down the Valley Pike from Strasburg. Banks deployed at Winchester to slow the Confederate pursuit. Jackson enveloped the right flank of the Union Army under Maj. Gen. Nathaniel P. Banks and pursued it as it fled across the Potomac River into Maryland. Jackson's success in achieving force concentration early in the fighting allowed him to secure a more decisive victory which had escaped him in previous battles of the campaign. First Winchester was a major victory in Jackson's Valley Campaign, both tactically and strategically. Union plans for the Peninsula Campaign, an offensive against Richmond, were disrupted by Jackson's audacity, and thousands of Union reinforcements were diverted to the Valley and the defense of Washington, D.C.