THE ARTILLERY

The Union Army entered the war with a strong advantage in artillery. It had ample manufacturing capacity in Northern factories, and it had a well-trained and professional officer corps manning that branch of the service. Field artillery in the American Civil War refers to the important artillery weapons, equipment, and practices used by the Artillery branch to support the infantry and cavalry forces in the field.

The basic unit of Union artillery was the battery, which usually consisted of six guns until after Gettysburg when they changed to 4 gun batteries because of it was easier to move a smaller battery around a battlefield. Attempts were made to ensure that all guns in a battery were of the same caliber, simplifying training and logistics. Each gun, or "piece", was operated by a gun crew of eight, plus four additional men to handle the horses and equipment. Two guns operating under the control of a lieutenant were known as a "section". The battery of guns was commanded by a captain. Artillery brigades composed of five batteries were commanded by colonels and supported the infantry organizations as follows: each infantry corps was supported directly by one artillery brigade and, in the case of the Army of the Potomac; five brigades formed the Artillery Reserve.

At the start of the war, the U.S. Army had 2,283 guns on hand, but only about 10% of these were field artillery pieces. By the end of the war, the army had 3,325 guns, of which 53% were field pieces. The army reported as "supplied to the army during the war" the following quantities: 7,892 guns, 6,335,295 artillery projectiles, 2,862,177 rounds of fixed artillery ammunition, 45,258 tons of lead metal, and 13,320 tons of gunpowder.