Notes about Civil War Union Artillery Batteries

[The following borrows heavily from Wikipedia]

The basic unit of Union artillery was the battery, which usually consisted of six guns, commanded by a captain. By 1864, it was not unusual for Union Army batteries to be reduced to four guns, due to shortage of available horses.

Artillery brigades were composed of five batteries, of six guns each, were commanded by a colonel. After 1863, the usual makeup of a Union army corps was three divisions of infantry and one brigade of artillery.

In the Army of the Potomac, an additional five brigades formed the Artillery Reserve, the use of which was directed by the Army commander, not by the infantry corp commander. The use of an A Artillery Reserve@ allowed artillery to be massed in support of the entire army’s objective, rather than being dispersed all across the battlefield.

A gun, or “piece”, typically was operated by a gun crew of nine. (There were three drivers for each six-horse team, who rode the horses on the left side.) Two guns operating under the control of a lieutenant were known as a “section”.

Each gun in the section was supported by a caisson which carried two ammunition chests, plus a limber for the caisson, which limber had one additional ammunition chest. Typically, there were available about 1,200 rounds for the battery going into battle, which would be divided into the sections according to the number of guns in the battery.

Horses were required to pull the enormous weight of the cannon and ammunition (close to two tons for a cannon and its attached limber chest of ammunition). On average, each horse pulled about 700 pounds (317.5 kg).

Each gun in a battery used two six-horse teams: one team pulled a limber that towed the gun, the other tea, pulled a limber that towed a caisson. The limber was a two-wheeled carriage that carried an ammunition chest. It was connected directly behind the team of six horses and towed either a gun or a caisson. In either case, the combination provided the equivalent of a four-wheeled vehicle, which distributed the load over two axles but was easier to maneuver on rough terrain than a four-wheeled wagon.

The large number of horses posed a logistical challenge for the artillery, because they had to be fed, maintained, and replaced when worn out or injured. The average horse only lasted eight months before death.

The battery of six guns was commanded by a captain. The captain had command over as many as 170 men and 98 horses in a six gun battery with six horse teams. Above the 70 or so men needed to operate the guns and handle the horses moving the guns, additional men were needed to handle and supply the ammunition during the battle, and also to handle and move guns, horses, and limbers.. Batteries were self-sufficient units, so therefore, teamsters for supply wagons, blacksmiths and farriers, and various other support and administrative personal were included in each battery. In addition, batteries retained a number of extra men above the minimum required for the battery to function properly. These men were assigned to the batteries for training and for replacement of hospitalized sick, and furloughed men of the battery, and C more importantly C for quick replacement of battle casualties.

Section Chiefs were first or second lieutenants who had command of, and responsibility for, their respective sections consisting of two platoons of persons to fire two cannons (40 men top average). Sections also included their two cannon, two caissons, four limbers, and 20 to 30 horses, plus the men to handle that equipment and those horses. During battle a section chief sometimes, on order of the captain, dismounted to direct his section’s fire, otherwise he directed the section from horseback. (All officers were mounted in a field artillery battery.)

During the Civil War, artillery fire accounted for most of the casualties, of both Union and Confederate forces.

Canister shot was the deadliest type of ammunition, consisting of a thin metal container loaded with layers of lead or iron balls packed in sawdust. Upon exiting the muzzle, the container disintegrated, and the balls fanned out as the equivalent of a shotgun blast. The effective range of canister was only 400 yards (370 m), but within that range dozens of enemy infantrymen could be mowed down. Even more devastating was “double canister”, generally used only in dire circumstances at extremely close range, where two containers of balls were fired simultaneously.

The Rhode Island 1st Light Artillery consisted of eight batteries. They were equipped with not only six artillery pieces to a battery, but also, some of them, like Battery E, had additional howitzers or other additional specialized field artilery pieces available to be used.