In March 1862, he fought in the Shenandoah Valley, commanding a brigade at the Battle of Kernstown. On the second day of the fighting at Kernstown, he temporarily assumed command of the division of wounded Brigadier General James Shields, and then pushed back Stonewall Jackson in a successful counterattack. It was one of the first repulses that Jackson had suffered. In recognition of Kimball's performance, he was promoted to brigadier general on April 16, 1862. With the victory at Kernstown, Kimball had now participated in early Civil War defeats of both Robert E. Lee and Thomas J. Jackson.