Gustavus Woodson Smith a major general on September 19, he served in Northern Virginia as a divisional and "wing" commander, and fought in the Battle of Seven Pines near Richmond during the Peninsula Campaign. On May 31, 1862, Smith briefly took command of the Army of Northern Virginia after Gen. Joseph E. Johnston was wounded at Seven Pines, due to his being the senior major general in Johnston's army. However, Jefferson Davis replaced him with Robert E. Lee the following day, June 1. On June 2, Smith became ill and took a leave of absence to recuperate. In late August, Smith returned and
Army of Northern Virginia Gen. J. E. Johnston as it was joined by the Army of the Shenandoah on July 20, 1861, when command was relinquished to General J. E. Johnston. The following day this army fought its first major engagement in the First Battle of Manassas. With the merging of the Army of the Shenandoah, Gen. Joseph E. Johnston took command from July 20, 1861, until May 31, 1862. Under the command of Johnston, the Army immediately entered into the First Battle of Manassas. On October 22, 1861, the Department of Northern Virginia was officially created, officially ending the Army of the Potomac.