Army of Northern Virginia 20 and July 21, the Army of the Shenandoah and forces from the District of Harpers Ferry were added. Units from the Army of the Northwest were merged into the Army of the Potomac between March 14 and May 17, 1862. The Army of the Potomac was renamed "Army of Northern Virginia" on March 14. The Army of the Peninsula was merged into it on April 12, 1862. Robert E. Lee's biographer, Douglas S. Freeman, asserts that the army received its final name from Lee when he issued orders assuming command on June 1, 1862. However, Freeman does admit that
First Corps, Army of Northern Virginia charge of the Left Wing. With the authorization of corps later that year, the Right Wing was redesignated as the First Corps. At this time, Longstreet's corps contained twenty-one brigades organized into five divisions under major generals Lafayette McLaws, Richard H. Anderson, George E. Pickett, and John B. Hood, and Brigadier General Robert Ransom, Jr. Note: see Fredericksburg order of battle for the command structure of the Army of Northern Virginia at this time. The Battle of Fredericksburg was fought in and around Fredericksburg, Virginia, starting on December 11 and concluding December 15, 1862, between Lee's Army of Northern Virginia