A Primer on American Civil War Field Artillery
civil war artillery piece
I'm guessing that this is a 3" ordnance rifle, primarily from the curved shape of the breach.  I'm not sure where I took this picture, but it could be in Tennessee or Northern Georgia.  Let me know if the scene looks familiar to you.

In early years of my American Civil War gaming I was overwhelmed by the variety of artillery described in the various rulebooks. In many cases the names given the various weapons in the rulebooks were inaccurate or contradictory. This was especially true for several types that were modified or converted to a different type. Fortunately, as the years went by I came across several reference works, that more or less clearly described the weapons of the era. The intent of this article is to present a concise summary of the major types used during the war with some notes as to origins, usage and effectiveness. I will only deal with field artillery here, as naval, siege and garrison artillery are quite involved subjects in themselves.

One of the first things that will confuse you is the reference to artillery by caliber (in inches) and weight of solid shot (in pounds). A general rule I use is to categorize smoothbore artillery by weight of shot and rifled artillery by caliber. Smoothbores had a long history of firing cast iron solid shot whose weight depended almost entirely upon the caliber of the weapon. Rifles fired elongated projectiles that could vary in weight depending upon length and size of bursting charge thereby forcing the gradual change to measurement by caliber which we use up to today. Some smoothbores, such as the 6pdr gun, model 1941, were converted to rifles during the war. The result was a halfbreed that had neither the caliber of a typical rifle nor the poundage rating of a typical smoothbore.

The vast majority of Civil War artillery was of two main types. They were the Napoleon and the 3" rifles. Together the two types constituted 80 to 90 percent or more of the field artillery of the major armies by the middle of the war. The rest of the stuff was an odd assortment of types. The stuff that confuses most of us.

The most famous of the two main types was the Napoleon. It was a direct copy of a French gun-howitzer designed in 1853 and named after Napoleon III. The French intended it to replace both howitzers and guns, each which was designed to fire different types of ammunition. Howitzers fired case, and shells using a smaller charge of powder. Guns fired solid shot with a larger charge for more range and punch. Both fired canister. During the war, the Napoleon proved very effective at short range when loaded with canister. Since most of the engagements occurred at this range, it remained a popular weapon to the end of the war. However in artillery duels against rifles at ranges over 1000 yards, it was hopelessly outclassed because of limited accuracy.

The Napoleon was not a light weapon, weighing some 1200 pounds for just the gun tube. Together with the 1200 pound carriage, the total 2400 pound weight is heavier than a car I have owned. That is not counting the weight of the limber or horses. One of the reenactments I was in, had a "friendly" artillery piece move down the road I was in formation on. Let me tell you that a six horse team trailing an artillery piece can be quite intimidating (at least to a greenhorn). It took no time at all for us to get off the road.

The second major type of field artillery were the 3" rifles. I include three separate weapons in this category because they were essentially equivalent. These three are the 3" ordinance rifle, the 2.9" and 3" Parrott rifles.

The 2.9" Parrott was the first of these weapons to show up on the field of battle in 1861. It was made of cast iron and had the distinctive reinforcing band of wrought iron at the breach. Parrotts were not always reliable. In other words they had a slight tendency to explode when fired! Later in the war, the 3" ordinance rifles became the standard rifle for the Union. With the two weapons only .1" different in caliber, ammunition supply problems were needlessly complicated. On at least on one documented occasion, (this one in the Confederate army), artillerymen attempted to use the 3" ammunition in the 2.9" Parrott rifle. The result was a shell jammed halfway down the barrel of several cannon. The 2.9" Parrotts in Union service were withdrawn from the field. At least half were rebored to the 3" standard caliber. Parrott production changed the from 2.9" caliber weapons to 3" caliber weapons in April 1863. Performance wise, Parrotts were fine weapons with a range of over 1.5 miles firing the Hotchkiss or Parrott shells. Like all rifles of the day, performance with canister was less than with smoothbores.

Being produced first in 1861 the 3" Ordnance was the most popular rifle of the war. It was made from wrought iron and proved very reliable. It is also known as the 3" Rodman, from the process used to make it. Although it did not fire a shell quite as far as a Parrott, it was a little lighter and well respected for it's accuracy. Pointing was the word used during the period for aiming artillery. The word is pretty descriptive of the process used. The results had to be inconsistent at best. The differences between Parrotts and 3" ordnance were insignificant when normal human error is factored into the equation. Hitting a specific target over any range greater than a mile had to be pretty much a matter of luck.

The 3" Ordnance Rifle weighed around 830 pounds. Being so light made it the choice of Union horse artillery, where maneuverability was extra important. Shells fired from rifled artillery had a tendency to bury into soft ground before exploding. That is if they exploded at all. I remember overhearing a couple of relic hunters talking several years ago. They had discovered a couple of shells buried at an obscure battlefield. They could tell where they were fired from, and even guess about who fired them, by the orientation of the shells in the earth.

Other rifles used by both sides included several types of smoothbores that were rifled. These creations sometimes didn't work too well, but they were used until more standard rifles could be made in quantity. The primary weapon that was altered was the 6pdr gun Model 1841. It was rifled in one of two fashions. One method was without altering it's basic caliber, 3.67 inches. The other was to bore it to 3.8 inches and rifle it in the "James" fashion. Hence it became a James rifle. There were also some cannon specifically cast as James rifles. James rifles threw a 14 pound projectile. Few were produced after 1862.

Also a 3.67" Parrott which threw a 20 pound shell was used by both sides. Weighing in at some 1750 pounds, it was not lightweight and didn't show up in mass quantities in the field even though almost 300 were made.

The North had a battery of Whitworth 2.75 inch breach-loading rifles. They were never used in combat although McClellan took them along on the Peninsular Campaign. The South did use breech and muzzleloading Whitworths in the field. A battery with Lee's army was used for long range sniping and harassment. Whitworths had limited usefulness because of the small bursting charge in the hexagonal shell. Also breachloading did not achieve all the desired results until automatic recoil systems were developed. When fired, the gun would kick back six feet or more. It would then have to be manhandled back into position and "pointed" again.

The North used one other type of rifle called the Wiard. It was a unique design that was mounted in a carriage that allow elevation of up to 35 degrees. The Wiard rifle came in two sizes, a six pounder and a 12 pounder with bores of 2.6 inches and 3.67 inches, respectively.

The South imported two other makes of rifles in limited quantities. These were Armstrong and Blakely rifles. The Armstrong was a 3" rifle that came both in breachloading and muzzleloading versions. The Armstrongs were roughly comparable to the Whitworths in that they were imported in limited quantities, used special ammunition and were highly regarded by the Southerners that were exposed to them. One does have to wonder how they managed to supply the unique ammunition to the imported weapons they used. The Blakely field rifle existed in at least 9 different types. The most common versions were a 12 pounder and a 18 pounder of 3.5 inch and 4 inch caliber's, respectively. All Blakely`s were muzzle loading rifles. The most unique aspect of their design was a recoil that had a tendency to destroy carriages. This was due primarily to the light weight of the weapon.

The Confederates also manufactured several Mountain Rifles of 2.25 inches caliber. They were designed to fit on the 12 pounder Mountain Howitzer carriage. This rifle and carriage could be broken down and packed on mules for transportation in rough terrain.

The remaining weapons I will mention were obsolete smoothbore designs. They were pulled out of inventory to meet the needs of the rapidly growing armies during the first stages of the war.

There were 2 sizes of guns that were replaced by the Napoleon. These were the 6 pounder and 12 pounders. They weighted around 880 and 1800 pound respectively. Both pieces differed little from weapons used in the American Revolution. Although there were many variations in these guns, the Model 1841 pattern of each piece was the most common pattern around at the start of the American Civil War. These weapons were made of bronze, except for a period between 1819 and 1841 when they were made of cast iron. For gaming purposes, one should not worry about which pattern, which unit had. Functionally they were all identical.

civil war artillery piece
I think I took this picture on top of Lookout Mountain.  The gun looks like a 6 pounder

Three kinds of howitzers were replaced by the Napoleon. These are the 12, 24 and 32 pounders. Howitzers were designed to fire case or shell. This kind of ammunition had thin walled shells. To prevent it from being destroyed by the discharge of the cannon, howitzers used smaller powder charges. This smaller powder charge allowed a thinner walled barrel which resulted in a lighter weapon.

The last weapon I will mention was the 12 pounder mountain howitzer. It was designed to broken down and carried by pack mules in broken country. One unique feature was that it's canister ammunition consisted of 148 .69 caliber balls. That is far more than the 27 balls included in the 12 pounder field gun's canister load. I think it can be safely assumed that the mountain howitzer had a role in point defense against storming parties. That was probably it's main role during the war.

Other types of artillery may have made an appearance now and then during the war, but this list should account for 95% of the field pieces used during the war. I hope that this short article can help gamers have a better understanding of what they are fighting with. For more information on these and other weapons of the Civil War I can recommend the following sources.

Gibbon, John. The Artillerist's Manual. New York: D. VanNostrand, 1860. Reprint. Westport, Connecticut: Greenwood Press, 1970.

Provides much interesting information on everything from how to make war rockets to the evolution of the minie ball. Gives you a look into the mind of a artilleryman just before the war.

Hazlett, James C. & Olmstead, Edwin & Parks, M. Hume. Field Artillery Weapons of the Civil War. Newark: University of Delaware Press, 1983.
Ripley, Warren. Artillery and Ammunition of The Civil War. New York: Promontory Press, 1970.

These two sources provide a great deal of information about Civil War artillery. Field Artillery Weapons is more specifically directed toward field artillery and is a little more up to date with current knowledge. It also provides a reference on where cannons were located at the time of publication. Artillery and Ammunition is a little more general in nature, but provides a nice set of tables at the back of the book describing each class of weapon covered.

Thomas, Dean s. Cannons. Arendtsville, Pa: Thomas Publications, 1985

Inexpensive softcover which provides a good introduction to Civil War artillery weapons and usage.

Table of common (and some uncommon) weapons used during the American Civil War. Use the numbers made column as a rough guide, not gospel.

Name Caliber Shot Range elevation Number In North America
12 Pounder Gun (Nap) 4.62" 12# 1800 Yards 5 deg. 1100
2.9 & 3 inch Parrott 2.9,3"  10#  2000 Yards  5 deg.  630 
3 inch Ordinance Rifle  3"  10#  1835 Yards  5 deg.  912 
Rifled 6 Pounder Gun  3.67"  12#  1700 Yards  5 deg.  31 
James Rifles  3.8"  14#  1700 Yards  5 deg.  406 
3.67" Parrott  3.67"  20#  2100 Yards  5 deg.  296 
Whitworth  1.7",1.92"  3#  few 
Whitworth  2.17"  6#  10000 Yards  35 deg.  few 
Whitworth  2.75"  12#  2800 Yards  5 deg.  few 
Wiard  2.6"  6#  60 
Wiard  3.67"  12# >7200 Yards  35 deg.  18 
Armstrong  3"  12#  3961 Yards  10 deg.  few 
Blakely  3.5"  12#  1760 Yards  7.5 deg.  few 
Blakely  4"  18#  few 
C.S. Mountain Rifle  2.25"  few 
6 Pounder Gun M 1841  3.67"  6#  1523 Yards  5 deg.  700 
12 Pounder Gun M 1841  4.62"  12#  1663 Yards  5 deg.  few 
12 Pounder How M 1841  4.62"  12#  1050 Yards  5 deg.  250 
24 Pounder How M 1844  5.82"  24#  1322 Yards  5 deg.  65 
32 Pounder How M 1844  6.4"  32#  1504 Yards  5 deg.  25 
12 Pounder Mt. Howitzer  4.62"  12#  1005 Yards  5 deg.  400