was later promoted to colonel and given command of the 9th Alabama Infantry Regiment on July 9. Wilcox joined Brig. Gen. Joseph E. Johnston's Army of the Shenandoah with his regiment on July 16, and marched to Manassas to reinforce Brig. Gen. P.G.T. Beauregard's Army of the Potomac just before the First Battle of Bull Run on July 21. On October 21, he was promoted to brigadier general and placed in command of a brigade comprising the 3rd Alabama, 1st Mississippi, and 1st Virginia infantry regiments along with an artillery battery. The brigade was assigned to Maj. Gen. James Longstreet's division of the First Corps, Army of Northern Virginia. During the 1862 Peninsula Campaign, Wilcox played a prominent role at the Battle of Williamsburg on May 5. At the 1862 Battle of Seven Pines, Wilcox commanded two brigades, and at Battle of Gaines' Mill on June 27 he led three—his own, Featherston's, and Pryor's. On June 30 at the Battle of Glendale during the Seven Days Battles, nearly every regimental officer in Wilcox's command was killed, and Wilcox himself had his clothing pierced by six bullets, but he somehow escaped injury. The loss in Wilcox's brigade was heavier in the Seven Days Battles than of any other brigade in Longstreet's division. After Longstreet was elevated to corps command, Wilcox got half of his division. He led it to Second Bull Run, but was held in reserve and saw no serious action. In the Maryland Campaign, Wilcox was returned to brigade command and his division merged with Richard H. Anderson's. He fell ill and spent the Battle of Antietam resting in Martinsburg, Virginia, leaving Colonel Alfred Cumming to command his brigade during that battle. As a part of the division of Maj. Gen. Richard H. Anderson at the Battle of Chancellorsville in May 1863, Wilcox's brigade was instrumental in delaying the Union VI Corps in its drive west from Fredericksburg, Virginia, slowing them at the Battle of Salem Church. Shortly after the battle, Wilcox and his brigade moved with Anderson's division to the newly created Third Corps, under Lt. Gen. A.P. Hill on May 30. Gettysburg Wilcox and his command participated in the Battle of Gettysburg in the summer of 1863. On the battle's second day, July 2, his charge against a weakened Union line was met (and held off) by a suicidally brave countercharge from the 1st Minnesota Volunteer Infantry.