Civil War Field Artillery


With each gun served by a well-drilled crew, the 5th U.S. Artillery decimates Lt. Gen. Robert E. Lee's charging infantry and helps save the Army of the Potomac from annihilation on July 1, 1862, in Malvern Hill, by Don Stivers.

Field artillery during the Civil War was far different from what it is today, or even from what it was in World War I. The major difference between Civil War and 20th century field artillery is that the former was a direct-fire weapon. There were no spotters calling down fire on distant targets by means of complex mathematical computations of ranges and angles. Nor was there any recoil mechanism on the guns; they bucked and jumped with every round and had to be retargeted after every shot.

Civil War artillery had far more in common with its Napoleonic ancestors. And Napoleon, an artillerist himself, owed much of his success to the artillery reforms introduced into the French army during the 18th century by Jean Baptiste Vaquette de Gribeauval, who lightened the cannon and standardized a relatively small number of calibers and lengths. Also in the Napoleonic era, civilian teamsters, who in previous wars would take the guns to the battlefield but would not hang around for the fight, were replaced by soldiers so that the guns could be shifted and maneuvered on the battlefield. The resulting "light artillery" had an enhanced maneuverability and firepower that added greatly to its effectiveness. The British added another refinement by replacing the old double-trail carriage with the lighter single, or block, trail.

In 1838, Secretary of War John C. Calhoun decided to equip one company of each of the four artillery regiments of the United States Army as light artillery batteries. And the resultant light artillery of the Regular Army had a great deal to do with the American victories in the Mexican War eight years later.

Light artillery was almost unchanged from the Mexican War to the Civil War, except that two new and improved types of cannons were just coming into service in 1861. Field artillery traditionally consisted of two basic types of cannons: guns and howitzers. The guns fired projectiles with a relatively high velocity and a relatively low, flat trajectory. Howitzers had short barrels and used smaller powder charges, thus firing with a lower velocity and a higher, arching trajectory. For long-range work, guns fired a type of ammunition called solid shot, or shot, which was nothing more than a solid iron ball similar to that used in shot-putting. Howitzers, however, fired shells - hollow iron balls fills with gunpowder and fixed with a fuze. Because of their shorter barrels and reduced powder charges, howitzers could be used in considerably larger calibers than field guns and still be light enough to keep up with a marching army and maneuver on the battlefield.

Guns and howitzers both had their advantages and disadvantages. Guns, because of their higher velocities and solid (and therefore denser) shot, were more accurate. Although less likely to hit a given target, howitzers could, with their exploding shells, often do more damage when they did hit. Howitzers were especially useful for bombarding wooden buildings or bridges because their exploding shells would often start fires in such materials.

Guns were usually known by the weight of the solid shot they threw. Thus a 6-pounder fired a solid iron shot weighing approximately 6 pounds. Howitzers were either known by their caliber, such as the French 6-inch howitzer, or by the size of solid shot they could throw if using solid shot (even though they did not), such as the American 24-pounder.

The basic unit of artillery was the battery or company. Technically, the term "battery" referred to the collection of guns, and the soldiers manning those guns formed a company. But this was a fine distinction that was usually ignored. Traditionally, batteries of field artillery contained a mixture of guns and howitzers. A pre-Civil War battery of the U.S. Army contained either four 6-pounder guns and two 12-pounder howitzers, or, more rarely, four 12-pounder guns and two 24-pounder howitzers.

In 1857, however, the United States copied a new French 12-pounder design that was known variously as the Napoleon (after Emperor Napoleon III, who had sponsored the French design), the light 12-pounder, or the 12-pounder gun-howitzer. As the latter name implies, it combined the best features of guns and howitzers, firing both shot and shell on a medium trajectory. It quickly replaced the older, heavier 12-pounder gun and soon began replacing the 12-pounder howitzer and 6-pounder gun, although these types were never completely phased out during the war. Robert E. Lee at one time suggested melting down 6-pounders to get the metal to make more Napoleons.

Another new type of cannon just coming into use at the start of the war was the rifled gun. Rifling the inside of the barrel of a cannon with spiral grooves and using a shot or shell that tightly fit the rifling imparted a spin to the projectile that greatly improved its range and accuracy. The ammunition for rifled guns, in order to be able to grip the rifling, was cylindrical rather than spherical, except for its pointed nose. Like the Minie bullet for the rifled musket, most ammunition for rifled guns loaded easily but expanded to take the rifling when it was fired.

The barrels of guns and howitzers in field artillery were traditionally made of bronze or brass - the two terms were used interchangeably. It was a lighter metal than iron and did not rust, but it was not well suited for rifles because the rifling grooves in bronze guns tended to wear down fairly quickly. General Charles T. James devised a methodology of rifling old bronze smoothbore guns and developed ammunition for them, but they were never popular. Like all rifles, they fired elongated; and thus heavier, projectiles. A given tube, or barrel, doubled its old rating. That is, a 6-pounder gun became a 12-pounder James rifle, and a 12-pounder gun became a 24-pounder rifle. This led to a confusion in terminology, since the same gun could be referred to as a rifled 6-pounder or a 12-pounder rifle.


These 12-pounder howitzers were captured by Union forces near Chattanooga, Tennessee, in November 1863, but the Federals were so well-equipped that they could "park" them.

Most rifled guns were made of iron because the rifling in iron barrels was far more durable. Two types predominated in the Union Army: the Parrott rifle and the Ordnance rifle. Parrott rifles came in many sizes, from the giant 150-pounder on down, but in the field artillery only the 10-pounder and the 20-pounder were used. Parrotts consisted of a cast-iron tube with a wrought-iron band shrunk around the breech to protect the area subjected to the greatest pressure by the powder charge. The 3-inch Ordnance rifle was a better piece, with the entire tube being made of wrought iron, thus eliminating the need for the breech band.

The 10-pounder Parrott originally had a bore diameter of 2.9 inches, but this was later changed to 3 inches so that the same ammunition would fit both it and the 3-inch Ordnance rifle. The 20-pounder Parrott had a 3.67-inch bore, the same as the old 6-pounder bronze smoothbore. But the 20-pounder was considered somewhat heavy for field use and was not much more effective than the 10-pounder, so it was never very popular.


Soldiers of Company L, 2nd New York Volunteer Heavy Artillery stand by one of their two 24-pounder howitzers.

The Confederates used the same types of rifles when they could capture them. The also imported a few British-made Blakely, Armstrong and Whitworth rifles in various calibers. Many of these were breechloaders. Loading from the breech allowed the guns to use ammunition fitted to the rifling (instead of expanding like a Minie bullet), which greatly increased their range and accuracy.

Because of their superior range and accuracy, rifled guns were highly prized at first. Experience showed, however, that opportunities to use the extra range did not often arise in the wooded terrain where most of the war was fought. And there were three drawbacks that offset the superior accuracy, two at long range and one at short range.

At long range, one problem was with the nature of the exploding shells used by rifles. Because of the higher velocity of rifles, the crude time fuzes of the era might explode the shell long before or long after it had reached the target. Therefore, most rifles used shells with percussion fuzes that exploded on contact. The velocity was so high, however, that the shells often penetrated several inches into the ground before exploding, thus doing little damage. Also, over relatively flat and hard terrain, spherical shot could be made to bound along just above the ground, greatly increasing its range and effectiveness. This could not be done with the oblong shot of rifled guns.

At short range, both guns and howitzers used a form of ammunition known as canister, or case shot. This consisted of a cylindrical container - a canister - filled with several small iron or lead balls. This, in effect, turned the cannon into a huge shotgun, and it was by far the most deadly ammunition available. However, because rifles had smaller bores than comparable smoothbores, they spread their canister shot over a smaller area.

During the Napoleonic era, the British developed a type of ammunition known as spherical case shot, or shrapnel (named for the British general who invented it). It combined some of the deadly effects of canister with the range of shell, and consisted of a thin spherical shell containing several small iron or lead balls, a small charge of powder just powerful enough to burst the shell, and a fuze. If the fuze was cut just right, the shell could burst just above and ahead of the target, spewing it with the small shot. This type of ammunition was not suitable for rifled guns, however, because their high velocity made it next to impossible to get the shell to explode at the right spot.

Some artillerymen preferred the rifled guns, while others preferred the Napoleon, but they all seemed to prefer one or the other to the old howitzers and smoothbore guns. By the spring of 1864, the Union Army of the Potomac had weeded out all types except the Napoleon, the 3-inch Ordnance rifle and the 10-pounder Parrott rifle. Western armies, however, were not so fortunate. The Confederates also kept a wide variety of weapon types. Even in Lee's Army of Northern Virginia, there were many 12-pounder howitzers and even a few 20-pounder Parrotts and British Whitworths.

Confederate batteries usually contained a mixture of two or more types, which seriously complicated their supply problems. The Federals, at least in the Army of the Potomac, were very careful to avoid mixing types within batteries.

With the passage of time, batteries tended to dwindle from six guns to four, not from the loss of guns but from the loss of men. The Union Army of the Potomac tried to maintain 6-gun batteries for most of the war by detailing men from the infantry to reinforce the artillery. After battles were fought in the Wilderness and at Spotsylvania in May 1864, Lt. Gen. Ulysses S. Grant wanted to reduce the size of his columns by sending the reserve artillery to Washington, but Maj. Gen. Henry Hunt, the chief of artillery for the Army of the Potomac, talked him into reducing all the six-gun batteries to four-gun batteries instead.

Early in the war it was common for individual batteries to be attached to infantry brigades. But as the war progressed both sides tended to concentrate their guns at higher levels of organization. In 1862, Maj. Gen. George B. McClellan concentrated the Army of the Potomac's guns at the division level and retained a sizable artillery reserve at army level. In 1863, his successor, Maj. Gen. Joseph Hooker, took the guns away from even the divisions, forming artillery brigades at the corps level and expanding the artillery reserve to several brigades.

The Confederate Army of Northern Virginia formed artillery battalions, roughly comparable to the Union artillery brigades, but usually smaller. At first one was attached to each division, and each corps had two in reserve. Later the divisions' battalions were detached and added to the corps reserve.

Few Civil War battlefields, however, were open enough to allow the artillery to be deployed in the massed batteries typical of Napoleon's tactics. On those rare occasions when they were, however, such as at Malvern Hill and Gettysburg, they proved deadly and decisive, giving the Union Army a much needed advantage over the more poorly equipped and handled Confederate artillery.

This article was taken from: Lowry, Don.  “Civil War Field Artillery Bridged the Gap Between Napoleon and World War I.” (American’s Civil War, November 1994), 12, 16, 95, 96, and 98. It is used with permission.

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