Continuing with a look at the initial organization of the artillery supporting the Army of the Potomac. Last post in this set, I examined the desired ratio of guns to infantry. In August 1861, General William Barry offered a very convoluted description of the types of guns he wanted for the Army of the Potomac:
… Three pieces to 1,000 men – two-thirds guns of which one-fourth are 12-pounders, three-fourths are 6-pounders, and of each which one-half are rifled; one-third howitzers, of which one-eighth are 32-pounders, one-eighth are 24-pounders, and three-fourths are 12-pounders, the whole distributed as follows:
For the infantry, two pieces to 1,000 men – light 12-pounders, Parrott 10-pounders, James 13-pounders, or 6-pounder guns and 12-pounder howitzers, assembled in mounted batteries.
For the cavalry, two pieces to 1,000 men – one-half 6-pounder guns horse artillery and mounted batteries and one-half 12-pounder mounted batteries.
For the reserve, one piece to 1,000 men – one-half 6-pounder horse artillery and mounted batteries and one-half 12-pounder mounted batteries. (OR, Series I, Volume 5, Serial 5, p. 580)
This is indeed hard to follow. If we consider (looking forward to a later post) the allocation of four batteries per infantry division, the target composition was one battery of 12-pdr Napoleons, two batteries with either 6-pdr guns or Parrotts, and one battery of 12-pdr howitzers. I would also point out that when Barry used the term “mounted” he referred to horse drawn artillery with the crews marching alongside, but not “horse” artillery where the crew rode with the guns.
The ratio of cannon types falls in line with the Instructions for Field Artillery. That manual called for a mix of artillery split with three-quarters being guns and one-quarter being howitzers. A quarter of the guns were supposed to be 12-pdrs, with the remainder 6-pdrs (with no provision for rifles in the 1861 manual). Of the howitzers, likewise a quarter were supposed to be heavy 24- or 32-pdrs, while the remainder were 12-pdr.
But in September 1862 Barry made a different recommendation:
That the proportion of artillery should be restricted to the system of the U.S. Ordnance Department, and of Parrott and the smooth bore (with the exception of a few howitzers for special service) to be exclusively the 12-pounder gun of the model of 1857, variously called the “gun howitzer,” the “light 12-pounder,” or the “Napoleon.” (OR, Series I, Volume 5, Serial 5, p. 67)
Clearly by the close of the Peninsula Campaign, Barry had found the 6-pdr guns useless. And not soon after September, the howitzers “for special service” dropped from the army’s artillery lineup as the 24- and 32-pdrs departed for the fortifications. A few 12-pdr howitzers remained in the Army of the Potomac, right up to Gettysburg. But these were the small minority against the large numbers of 12-pdr Napoleons.
Examination of the artillery batteries used through 1862 show that while the artillerists preferred Napoleons and iron rifled guns (Parrotts and Ordnance rifles), they made due with less desirable weapons. Recalling my notes on Federal cannon production, during the months Barry was chief of artillery for the Army of the Potomac, gun production surged. From the third quarter of 1861 to the first quarter of 1863, combined output of Napoleons, Parrott 10-pdrs, and 3-inch Ordnance Rifles remained above 100. The peak was the first quarter of 1862 with 82 Napoleons, 44 Parrotts, and 211 3-inch rifles delivered – the highest quarterly total for field guns in the war.
So with the need realized, Federal gun-makers responded.