At the end of the Valley Campaign, the brigade moved to reinforce General Robert E. Lee in the Seven Days Battles on the Virginia Peninsula. In the Battle of Gaines' Mill, the brigade assaulted the Federal right and helped Lee achieve a victory. In the Northern Virginia Campaign, the brigade suffered high casualties at the Battle of Cedar Mountain and General Winder was killed on August 9, 1862. Jackson personally rallied his old brigade and won the battle. The brigade would suffer more casualties in the Second Battle of Bull Run. On August 30, 1862, the Stonewall Brigade repulsed the attack of the Union's Iron Brigade and rallied for a counterattack. Its acting commander, Colonel William S. Baylor, was killed. Colonel Andrew J. Grigsby assumed command and led the brigade through the Maryland Campaign and the Battle of Antietam. The brigade defended the West Woods, where the fighting was so severe and attrition so high that Grigsby was commanding the division ("Jackson's Division") by the end of the day.