Civil War Artillery
Weapons

Basic Terminology

This is a schematic of a Napoleon, with the addition of a chamber purely for illustrative purposes. (From Dean S. Thomas, Cannons: An Introduction to Civil War Artillery)

Cutaway diagram of a cannon
a-knob; b-neck; c-vent; d - trunnion; e-muzzle swell; f-muzzle face; g-muzzle; h-rimbase; i-cascable; j-breech; k-chamber; l-bore

Common Weapons

The system of ordnance adopted by the U.S. Army in the 1840's was the picture of simplicity: six- and 12-pounder field guns, 12-, 24-, and 32-pounder field howitzers, 18- and 24-pounder siege and garrison guns, and 32- and 42-pounder sea-coast guns. To this were added columbiads and mortars. The principal modification to this system prior to the War was the substitution of the light 12-pounder as the field weapon of choice. However, this system was soon made obsolete by necessity and technology.

The Civil War required a sudden and massive mobilization of military resources. The immediate need for field artillery resulted in the use of a bewildering variety of pieces, ranging from superseded ordnance to modern experimental models imported from Great Britain. Amongst the array of Armstrongs, Blakelys, Wiards, and Whitworths, it is still possible to identify a relatively small number of makes and models of muzzle-loading cannon that served as the workhorses of the Civil War battlefield.

GUNS
As a term of art, "guns" are relatively long-barreled cannon designed to fire projectiles with a nearly flat trajectory.

Name Tube Length Tube Weight Bore Diameter Range1 Material
Six-Pounder, M1841 60 inches 884 pounds 3.67 inches 1520 yards Bronze
Light 12-pounder, M18572 66 inches 1227 pounds 4.62 inches 1620 yards Bronze
10-pounder Parrott, M18613 78 inches 890 pounds 2.9 inches 2000 yards Cast Iron
20-Pounder Parrott 89 inches 1750 pounds 3.67 inches 2100 yards Cast Iron
3-inch ordnance rifle 73 inches 816 pounds 3.0 inches 1850 yards Wrought Iron

1At five degrees of elevation
2Familiarly known as the "Napoleon". It was also referred to as a "gun-howitzer", because it was capable of firing at a relatively high angle, like a howitzer, but this term is not strictly apt because it has no chamber.
3The M1863 10-pounder Parrott was slightly modified; the bore was increased to 3.0 inches, to make its ammunition consistent with that of the new 3-inch ordnance rifle, and the muzzle swell was eliminated. The Parrott is easily recognizable by the reinforcing band of wrought iron around the breech. Although there were several other types of cannon with similar reinforces (Wiards, Brookes, and British imports like the various models of Blakelys) the Parrott was by far the most common.

Section of Parrotts, with a
limber chest and guidon		 Napoleons, Battery H (DeGolyer's), 1st
Michigan Light Artillery, Vicksburg NMP


HOWITZERS
Howitzers are shorter-barreled cannon with a chamber at the base of the bore, designed to take a smaller charge. Their range is shorter and the trajectory of the projectile shows more arc.

Name Tube LengthTube WeightBore DiameterRange1 Material
12-Pounder53 inches778 pounds4.62 inches 1100 yards Bronze
24-pounder 65 inches 1318 pounds 5.82 inches 1325 yards Bronze
Mountain Howitzer 37 inches 220 pounds 4.62 inches 900 yards Bronze

1At five degrees of elevation

The Evolution of Ordnance

The Civil War accelerated the technological development of ordnance. Before the War, the typical cannon was a bronze, muzzle-loading smoothbore. Though such cannon were still in heavy use at the end of the War, it was apparent that the next generation of guns would be steel, breechloading rifles.

Rifles vs. Smoothbores
The principles of rifling had long been understood; the spin imparted to the projectile by forcing it into spiral grooves in the bore of the gun made it fly straighter, farther, and with more power on impact. Rifling of bronze guns was not an effective solution, because the friction of the ammunition wore down the rifling in that relatively soft metal. (Many older weapons, particularly the nearly obsolete 6-pounders, were rebored with rifling at the start of the War, and proved to be of very limited use after a very short time.) Effective rifled cannon required harder metal, but cast iron, the logical choice, was too brittle.

Early Breechloaders
As with rifling, the advantages of loading a cannon at the breech are fairly clear, as the men serving at the front of a gun could attest. Breechloading guns required a mechanism that was able to withstand the strain of firing and still operate smoothly and quickly to allow the next round to be fired. This required not only a superior material but expert machining. The famous Whitworth was an early but unreliable example, and its cannoneers not infrequently had to fasten the breech closed and load it from the muzzle.

A Comment on Materials
The disadvantages of bronze as an ordnance material have just been listed, and to them may be added its excessive weight. But bronze had for centuries the signal advantage of toughness; absent a serious defect in manufacture, bronze guns were reliable and safe. Superior smelting techniques developed during the early industrial revolution raised hopes that cast iron might be a suitable material for guns, and there were many experiments. However, the explosion of the Peacemaker aboard the Princeton halted the production of iron cannon in the United States for over a decade.
Reinforcement of cast iron at the breech was an obvious solution, but Robert Parker Parrott was the first to successfully turn out quantities of cast iron cannon. The novelty in his method was not in the reinforce, but in the method of attachment; the wrought iron band was allowed to cool in place while the gun was rotated, which allowed the reinforce to clamp on uniformly around the circumference of the breech. The resulting guns still did burst occasionally, but could be produced quickly and cheaply at a time when they were desperately needed; the cost to the government was about $187, versus about $350 for its nearest rival, the wrought iron 3-inch ordnance rifle. The Parrott system became the workhorse rifle of the artillery for the first years of the War, and continued to be produced in quantity even after the introduction of the ordnance rifle, which was preferred by many artillerymen. Advances in materials superseded both models within a few years; the steel rifle, of which the Wiard is one of the earliest examples, soon took over the field.

Carriages, Limbers and Caissons

This Number One carriage is shown carrying a 6-pounder.

A caisson hooked to its limber; note the extra wheel at the rear and the extra limber pole slung under the caisson.