Any firearms larger than small arms, which include handguns, muskets, and rifles, are called cannon or artillery. Cannons come in all shapes and sizes and are categorized as either smoothbore or rifled. Additional distinctions relate to the weight, in pounds, of the fired projectile; the size of a barrel’s bore diameter, or caliber; the method of loading (muzzle or breech); and the trajectory, or flight arc, of the projectiles. The short-barreled cannons called mortars had a high trajectory, and the long-barreled cannons called guns had a flat trajectory. The trajectory of a howitzer-a cannon with a barrel longer than that of a mortar but shorter than that of a gun-was in between that of a mortar and a gun.
Often, cannons were named after their inventors or after the factory that produced them. Examples include Dahlgren, Napoleon, Parrott, and Whitworth. Civil War cannons were made of bronze, iron, or steel. Both sides favored the Napoleon, a muzzle-loaded, smoothbore, 12-pound gun-howitzer. The Napoleon was named after Louis Napoleon-Emperor Napoleon III of France-who directed its development. The United States added the Napoleon to its arsenal four years before the start of the war. A versatile gun, the Napoleon was used both to attack and to defend positions. Effective up to 1,700 yards (1,554 meters), the Napoleon’s range extended another 800 yards (732 meters). This smoothbore cannon was capable of firing canister shot with deadly precision. Additionally, the weapon was comparatively light and easy to transport. This made it a popular component in artillery units.
The 10-pound Parrott was the most commonly used rifled artillery piece in the war. The Parrott could fire a projectile about 2,300 yards (2,100 meters) and packed a powerful punch against defensive works. The Union used rifled cannon such as the Parrot in the sieges of Vicksburg in 1863 and Atlanta in 1864. In order to fire accurately, however, gunners needed to spot their target visually. This limited the effective range of rifled cannon. Consequently, the shorter-ranged, smoothbore Napoleons provided sufficient accuracy for most Civil War artillery units.
Sizes of guns ranged from the small and easily portable howitzers (8-inch and 10-inch) to the large, heavy guns on naval ships. Both sides fired solid shot, or exploding shells, and chain shot. Chain shot consisted of two solid balls joined by a chain. Gunners aimed the chain shot at the masts of enemy warships, in the hope of disabling the ships. Artillery technology pointed the way to the warfare of the future, but it did not keep up with the technology of firearms. Because most breech-loaded cannons were undependable and more difficult to maneuver than muzzle-loaded cannons, almost all Civil War cannons were muzzle loaded.
Smoothbore cannon had a range of about one mile (1,609 meters). When rifling was added to artillery pieces, it increased their range. Many of the advances in artillery came in the kinds of shells the big guns fired, however. Rifled cannons had at least two distinct advantages over smoothbores: First, the rifled cannon could fire projectiles in a flat trajectory. Second, the same artillery pieces could fire on enemy targets from greater distances and deliver more firepower. Because smoothbore cannons remained effective in disrupting infantry charges, however, there was little need and no rush to convert to rifled cannons. Additionally, much of the fighting took place in wooded and hilly terrain, and smoothbore cannons performed well in those environments.
Defensive preparations offered some protection against Napoleons. This preparation forced attacking gunners to use other weapons to dislodge defenders. Breastworks-temporary fortifications made of earth, wood, or anything that provided cover-limited the effectiveness of artillery guns, because fieldworks made of earth absorbed much of the shock of the explosion. Howitzers overcame this defensive obstacle by increasing the angle at which the fired shell left the barrel and descended. A howitzer usually features a short barrel. An artillery gun fires shells at a relatively flat trajectory, but a howitzer fires shells at steep trajectories. A short-barreled mortar fires shells at an even greater trajectory. Howitzers offered the advantage of firing over defensive works and directly into the heart of the enemy camp.
Grape and Canister Shot
Several kinds of ammunition were fired from cannons during the Civil War. Two of these were intended for use against enemy troops: grapeshot and canister shot. Grapeshot was a collection of solid-shot balls wrapped in canvas or some other cloth and tied shut with a string. The term grapeshot came about from the fact that the ammunition pack looked like a cluster of grapes. When grapeshot was fired, the shock of the blast disintegrated the cloth wrapping and dispersed the shot in a scattered pattern along its trajectory. Such a projectile was a deadly weapon against infantry.
Canister shot was another kind of antipersonnel ammunition fired from cannons. Similar to grapeshot, canister shot is a kind of cannon version of a shotgun blast, in which loosely packed slugs are fired from an artillery gun. This type of shot was designed to disrupt advancing enemy troops by releasing a large number of balls at one time from each cannon. Canister shot usually was fired into a group of soldiers. A single round of canister shot was made up of a round, metal container filled with iron or lead balls. Packed in sawdust, the balls quickly scattered when a cannon fired the canister. If balls were in short supply, scrap metal, nails, wire, or anything made out of metal replaced the round shot. Generally, the cylindrical canister was made of tin. The ends were plugged with disks made of metal or wood. For larger cannons, the canister was made of iron. The entire can was usually coated with beeswax to waterproof it. A cartridge bag made of cloth and filled with gunpowder was fastened to one end of the canister. The gunpowder in the bag served as the charge that launched the round from the cannon.
A fired canister fragmented, spreading shrapnel and releasing the metal balls within it to clear a cone-shaped area with the blast. Within 250 yards, canister shot was an effective and deadly tool against enemy troops. A mass of infantry was no match for the destructive firepower of canister shot. During the Civil War, some artillery commanders used a technique in which cannons were aimed at the ground in front of advancing enemy troops. The exploded canisters struck the ground, and balls ricocheted off the ground, expanding the target area. Union artillery effectively used this technique at the Battle of Gettysburg against the Confederate troops who were attempting to take Seminary Ridge. Throughout the war, artillery units preferred canister shot to grapeshot, believing canister shot to be more effective.
The technology in artillery changed some tactics and affected the outcome of battles. Sometimes, however, commanders used the appearance of technology to deceive the enemy. One of the best– known instances of this sort of trick occurred during the 1862 Peninsular Campaign. Confederate general Joseph E. Johnston shaped logs to look like cannons, painted them black, and set them up in place of real cannons in his defenses near Centerville, Virginia. From a distance, the Union troops could not tell the difference. Union general George McClellan lingered, fearing to advance against such a powerful defensive position. The trick worked. It allowed Johnston and his men to retreat across the Rappahannock River. The so– called Quaker guns gave the false impression of technological strength. Johnston was not the only commander to use Quaker guns. Other Confederate commanders used the same technique. Union officers also employed logs masquerading as cannon to disguise retreats or other troop movements. Quaker guns proved to be an effective deterrent that allowed a force to withdraw unimpeded. As historian Maurice D’ Aoustand writes, “Strategically placed, these bogus batteries could effectively transform a thinly defended line into one that was bristling with cannon muzzles, and they were often instrumental in thwarting the enemy.” Thus, not all technology was new– or even real. Some of it was simply old– fashioned trickery designed to mimic the power of real technology.