In the spring of 1862, relying on faulty intelligence that under-reported the strength of the Union garrison at Winchester in the lower Shenandoah Valley, Confederate Maj. Gen. “Stonewall” Jackson marched aggressively north with his 3,800-man division. In Winchester, the 8,500 Federals were a detachment from the Army of the Potomac's Fifth Corps, and were commanded by Col. Nathan Kimball, who outnumbered Jackson more than two to one. Kimball established a defensive position on the Valley Turnpike and Middle Roads near Kernstown, just southwest of Winchester. Jackson sent one cavalry brigade forward on his right, and attacked Kimball with his left on the high ground of Sandy Ridge with two, and later three brigades, including his namesake Stonewall Brigade. Kimball counterattacked, but Jackson's men fought hard. The Confederate brigade commanders, running low on ammunition, began to pull back without Jackson's orders. Jackson tried in vain to rally his outnumbered and outgunned troops, but Kimball mounted no effective Union pursuit. Despite this Union victory in the first battle of Jackson's 1862 Valley Campaign, President Abraham Lincoln was disturbed by Jackson’s threat to Washington and redirected substantial reinforcements to the Valley, depriving McClellan’s army of those troops. McClellan claimed that the additional men would have enabled him to take Richmond during his Peninsula campaign.