The number of troops recruited for the Fifth Artillery, Two Hundred and Four of the line, being largely in excess of the standard for a single regiment, it was determined to organize a Sixth for similar duty. The men composing the latter, were principally from the counties of Allegheny, Butler, Westmoreland, Fayette, Washington, and Lawrence, and were organized at Camp Reynolds, near Pittsburgh, on the 15th of September, 1864, with the following field officers: Charles Barnes, Colonel; Joseph B. Copeland, Lieutenant Colonel; Robert H. Long, Joseph R. Kemp, and Frank H. White, Majors. Two days after its organization, it moved for Washington, and upon its arrival, was assigned to the Second Brigade of DeRussy's Division, which was garrisoning the defenses of the Capital. On the 29th, the regiment was detached from the division, and ordered to duty in guarding the portion of the Orange and Alexandria Railroad, lying between Alexandria and Manassas, the several companies stationed at intervals along the line, with headquarters at Fairfax Court House. Over this road, supplies for Sheridan's army were transported, and the regiment was charged with keeping open the part intrusted to it. It was an enemy's country, and infested with roving bands, military and civilian upon occasion, and to guard against surprise, and to be at all points superior to an attacking force, requiring incessant watchfulness and skill in the disposition and handling of the guards. Colonel Barnes was an experienced infantry officer, having served in the Ninth Reserve, and nearly all of both officers and men had been previously in the army. The discipline which had thus been acquired, now served a most important purpose; for it was only by the strictest attention to duty, and the exercise of sound discretion, that the wily and watchful enemy could be kept at bay. To go outside the lines, was almost certain death. On one occasion, three soldiers who had chanced thus to go, were fired upon by parties in ambush, and wounded, when, rushing up from their covert, the inhuman wretches stood with pistols in hand, over the bodies of the victims weltering in their blood, and fired into their breasts until they were quite dead.

About the middle of November-Sheridan having, in the meantime, cleared the Shenandoah Valley of the foe-this line of railway was abandoned, and the regiment was ordered back to the defenses of Washington, being posted at Ft. Marcy, Ward, Craig, Reno, Albany, Lyon, and others. Previous to this time, it had been armed and drilled as infantry. It was now instructed in heavy artillery service. Captain Gustavus L. Braun, who had served as an officer in the Second Artillery regiment, was appointed drill master, and under the strict discipline enforced by its Colonel, it soon became proficient like wise in this arm of the service. During the winter, and until a period was put to the war by the victorious armies of Grant and Sherman, it remained on duty in the forts covering the Capital. On the 13th of June 1865, it was mustered out of service at Fort Ethan Allen, and returning to Camp Reynolds, was, on the 17th, finally disbanded. Subsequently, Colonel Barnes, "for meritorious conduct during the entire war,' was brevetted a Brigadier General.

"History of Pennsylvania Volunteers, Vol. X, Pg 771-772" - Samuel Bates

Field & Staff Records
6th Regiment Pennsylvania Heavy Artillery / 212th Pennsylvania of the Line

The following company locations were taken from the Regiment's official records in the National Archives in Washington, D.C.