Barry and the Artillery Organization of the AOP: Part 4, Battery Compositions

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 types of guns William Barry preferred.  I’ll turn now to the third point in regard to artillery organization for the army.

Although in his August 1861 plan, Barry did not set a target for the number of guns issued to each battery, in September 1862 his report detailed such:

That each field battery should, if practicable, be composed of six guns, and none to be less than four guns, and in all cases the guns of each battery should be of uniform caliber. (OR, Series I, Volume 5, Serial 5, p. 67)

Here Barry made a departure from the Instructions for Field Artillery.  That manual actually specified three types of batteries:

  • 12-pdr Batteries with four 12-pdr (heavy) guns and either two 24-pdr or two 32-pdr howitzers.
  • 12-pdr (Light) Batteries with six 12-pdr “Napoleons.”
  • 6-pdr Batteries with four 6-pdr guns and two 12-pdr howitzers.

The manual worked from an authorization of six guns, with extension to eight allowed.  While the manual didn’t directly address rifled guns, those were issued in lieu of 6-pdrs for the light batteries.

I would give Barry the benefit of the doubt with regard to the battery compositions.  He’d seen the artillery in action at Manassas with a varied lot of guns.

Limiting batteries to a maximum of six guns per battery, offered many benefits both tactically and logistically.  Eight guns, with limbers, caissons, horses, and crews, required a lot of space on the battlefield.  The size of a battery thus made it an inciting target for the enemy.  When avoiding shots over the heads of friendly troops (which is often inevitable), the battery might also present a weak spot to infantry attack. Two or four less guns in the battery (assuming the remainder of those guns were grouped in another battery) presented a smaller footprint without sacrificing firepower.

Logistically, it was difficult enough to keep the ammunition chests of six guns full, much less eight.  Reducing to sizes of four to six eased some of the burden bore at the battery level.  Although arguably at the Army level 300 guns is 300 guns, logistically speaking, regardless of the battery size.  Still this reduced the number of considerations a battery commander or divisional chief of artillery had to juggle.

As for the uniformity of gun caliber, as seen from the previous post, Barry wanted that across the entire Army of the Potomac.  But only by mid-1863 did the army reach a proper level of gun caliber uniformity, with a predominance of  12-pdr Napoleons, 3-inch Ordnance Rifles, and 10-pdr Parrotts.


Barry and the Artillery Organization of the AOP: Part 3, Types of Guns

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.

Barry and the Artillery Organization of the AOP: Part 2, Ratio of Guns

Discussing the initial organization of the artillery within the Army of the Potomac, I offered an overview of the plan proposed by General William Barry, and approved by General George McClellan.  Again, there are some detail differences between Barry’s reports of August 1861 and September 1862.  One of those, although small, appears in the first detailed point provided by Barry – the ratio of artillery pieces to troops.

In August 1861, Barry feared the poor discipline of the volunteer infantry force. Thus he recommended, “…the artillery, to give them confidence and steadiness, is arranged upon the basis of three pieces to 1,000 men.”  He later predicted that ratio might drop by half as the troops gain in experience.  Thus the number of guns Barry desired for the army at Washington, D.C. was initially around six-hundred, but was willing to lower that figure to three-hundred to support a 200,000-man army.  (OR, Series I, Volume 5, Serial 5, p. 580)

But in September 1862, Barry would write, “That the proportion of artillery should be in the ratio of at least two and a half pieces to 1,000 men, to be expanded if possible to three pieces to 1,000 men.” (OR, Series I, Volume 5, Serial 5, p. 67)

For comparison, the Instruction for Field Artillery (which recall Barry was a co-author) offered:

The proportion of field artillery to other arms varies generally between the limits of 1 and 4 pieces to 1,000 men, according to the force of the army, the character of the troops of which it is composed, the force and character of the enemy, the nature of the country which is to be the theater of the war, and the character and object of the war. Similar considerations must regulate the selection of the kinds of ordnance, and the proportions of the different kinds.  (Instruction for Field Artillery, 1864 edition, page 3)

I conclude Barry was practicing exactly what he preached with regard to the ratios.  But honestly, I’ve always scratched my head at Barry’s offered ratios.  Based on a 3-to-1,000 ratio, a six-hundred gun artillery park would support a 600,000 man army!  McClellan’s dream!

However that number does seem more to scale if Barry was discussing the proposed number of guns for the entire army, and not just the Army of the Potomac.  I’ve never attempted to estimate the number of guns the Federals needed in the fall of 1861.  I would offer that by my figuring the whole Federal army needed around 950 guns by the fall of 1862 for the major armies, and at least a hundred more by the summer of 1863.   So perhaps 600 guns would be a good start.

Barry’s 1862 report offed some interesting figures comparing the artillery with the Army of the Potomac up to that point.  In July 1861 the “new” Army of the Potomac had thirty guns in nine batteries (imperfectly-equipped batteries as Barry notes).  In March 1862, Barry put the numbers at 520 guns in 92 batteries around Washington.  The Army of the Potomac moved to Fort Monroe in April with 299 guns in 52 batteries.  That increased to 343 guns in 60 batteries by the Seven Days in late June.

Consider that in September 1862 the Federal fought Antietam with 293 guns in 57 batteries (30 guns in another seven batteries were in the area but not engaged), supporting 75,000 troops – a four guns to 1,000 men ratio.   And in July 1863, when many would say the Army of the Potomac was at its peak of efficiency, training, and experience, it fought Gettysburg with 372 guns in 67 batteries, supporting 70,000 troops – over five guns for every 1,000 men.

My conclusion, based on the raw numbers deployed in the later battles, is that Barry’s ratio of three guns per 1,000 “green” troops was too low.