At 2:00 p.m. on July 21, 1861, various sections of Virginia artillery served with the Army of the Potomac under Beauregard and the Army of the Shenandoah under Johnston in the CSA. These included the Loudoun Artillery under Capt. Arthur L. Rogers, Wise Artillery under Capt. Ephraim G. Alburtis, Rockbridge Artillery under Capt. William N. Pendleton, Staunton Artillery under Capt. John D. Imboden, and Thomas Artillery under Capt. Philip B. Stanard. Gen. P.G.T. Beauregard said their guns occupied an open space at the eastern edge of the plateau, where thirteen pieces, mostly 6-pounders, were kept in action, alternating to some extent with each other and taking part as needed from the onset, displaying a capacity as artillerists that made them both the terror and admiration of the enemy.
