For this installment of my look into the initial organization of the artillery supporting the Army of the Potomac, I turn to the battery assignments suggested by General William Barry, the army’s chief of artillery. As with the battery compositions, Barry did not offer details to battery assignments in his August 1861 plan. However in September 1862 he recorded those assignments:
That the field batteries were to be assigned to divisions and not to brigades, and in the proportion of four to each division, of which one was to be a battery of regulars, the remainder of volunteers; the captain of the regular battery to be the commander of artillery of the division. In the event of several divisions constituting an army corps, at last one-half of the divisional artillery was to constitute the reserve artillery of the corps. (OR, Series I, Volume 5, Serial 5, p. 67)
Barry’s recommendation broke many traditional artillery assignments. In past wars, the American armies rarely took to the field in larger formations than divisions. And up to the middle of the 19th century, artillery lacked the capabilities offered with the new projectile technology. For many reasons assigning batteries to support individual brigades made sense in the Mexican War. But twenty years later, Barry and others saw this as a miss-allocation of resources.
By centralizing the guns at the division level, the artillery better achieved the concentration of fire called for in the Instructions for Field Artillery. The Federal order of battle for the Seven Days indicates Barry’s suggestion carried through to a point. Corps reserves were not established. But on the other side of the field, some Confederate brigades retained their assigned artillery batteries. Over the course of two years of war, both sides concentrated batteries at the division, then corps levels, in formations under the command of a single artillerist.
The stipulation to use regular army battery commanders in a “commander of artillery” role might sound like a regular army snub of the volunteers. But this ensured division commanders had a capable artillerist in a position to advise regarding artillery placement. Many of those division commanders of course were political appointees, who needed just such an opinion at arm’s reach. And this also brought several capable junior officers to the fore.