On June 26, 1862, President Abraham Lincoln issued a presidential proclamation that merged the forces commanded by major generals John C. Fremont, Nathaniel Banks, and Irvin McDowell, as well as those under Brigadier General Samuel D. Sturgis, to form the Army of Virginia, commanded by Major General John Pope.
Order Constituting the Army of Virginia
June 26, 1862
Ordered: 1st. 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.
2d. 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 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.
3d. The Army of Virginia shall operate in such manner as, while protecting western Virginia and the national capital from danger or insult, it shall in the speediest manner attack and overcome the rebel forces under Jackson and Ewell, threaten the enemy in the direction of Charlottesville, and render the most effective aid to relieve General McClellan and capture Richmond.
4th. When the Army of the Potomac and the Army of Virginia shall be in position to communicate and directly co-operate at or before Richmond, the chief command, while so operating together, shall be governed, as in like cases, by the Rules and Articles of War.