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
Army of Northern Virginia previous name, the Confederate Army of the Potomac) from June 20 to July 20, 1861. His forces consisted of six brigades, with various militia and artillery from the former Department of Alexandria. During his command, Gen. Beauregard is noted for creating the battle flag of the army, which came to be the primary battle flag for all corps and forces under the Army of Northern Virginia. The flag was designed due to confusion during battle between the Confederate "Stars and Bars" flag and the flag of the United States. Beauregard continued commanding these troops as the new First Corps under