On August 12, 1862, the U.S. War Department issued General Orders No. 103, codifying President Abraham Lincoln's June 26 order to create the Army of Virginia, Major General John Pope commanding.
General Orders, No. 103
WAR DEP’T, ADJUTANT GENERAL’S OFFICE,
Washington, August 12, 1862
The following is an order of the President of the United States, dated June 26, 1862.
1. – The forces under Major Generals Fremont, Banks, and McDowell, including the troops now under Brigadier General Sturgis, at Washington, shall be consolidated, and form one army, to be called the Army of Virginia.
2. – The command of the Army of Virginia is specially assigned to Major General John Pope, as Commanding General. The troops of the Mountain Department, heretofore under the command of General Fremont, shall constitute the First Army Corps, under the command of General Fremont; the troops of the Shenandoah Department, now under General Banks, shall constitute the Second Army Corps, and be commanded by him; the troops under the command of General McDowell, except those within the fortifications and city of Washington, shall form the Third Army Corps, and be under his command.
By ORDER OF THE SECRETARY OF WAR:
E. D. TOWNSEND, Assistant Adjutant General.