Model 1857 12-Pounder Napoleon Field Gun

The Model 1857 12-Pounder Napoleon Field Gun, officially called the “light 12-pounder gun” by the United States Army, was the most popular smoothbore cannon used during the American Civil War.^[1] The cannon was named after French president and emperor, Napoleon III, nephew of Napoleon Bonaparte.

The French Canon obusier de campagne de 12 cm, modèle 1853, also known as the Canon de l’Empereur, was a type of canon-obusier (shell cannon) or gun-howitzer developed in 1853 by the French army.^[2] It could fire ball, shell, canister or grapeshot which allowed it to replace all the earlier French cannons. It was of a cast bronze smoothbore design and could double as a howitzer. It was light enough to be pulled by a team of horses. At the same time it had enough firepower to destroy fortifications at a distance of a half-mile (805 meters).^[3] When it entered the service of Emperor Napoléon III it was named after him.^[3]

In 1857 the design was adopted by the U.S. Army as the light 12-pounder M1857.^[3] The Union made 1,156 units while the Confederacy made 501.^[4] Because they did not have the manufacturing capacity of the North, Confederates attempted to capture as many Union-made Napoleon 12-pounders as they could.^[4] The Confederate army also developed their own version. In 1863, General Robert E. Lee was so impressed by the M1857 that he had all six-pounders in the Army of Northern Virginia gathered up and sent to Richmond to be melted down and re-cast into 12-pounders.^[3] The Confederates kept producing 12-pounder Napoleons until the Union army captured the Ducktown copper mines near Chattanooga, Tennessee. This reduced Confederates bronze production.^[3] After that Confederate 1857s were cast of iron.^[5]

When first model 1857s were cast in Northern foundries they had two handles or "dolphins".^[6] After 1861 the dolphins were eliminated, the barrel was shortened from the French version, and it was made lighter.^[6] Like most cannons in use at the time, they were muzzleloading weapons.^[7] The Model 1857 12-pounder Napoleon with its bronze barrel made up 40% of the cannons on both sides.^[8] The U.S. version of the Napoleon could hit a target up to 1,700 yards (1,600 m) away.^[9] However they were most accurate at closer ranges of about 250 yards (230 m).^[9] It used a charge of 2.5 pounds (1.1 kg) of black powder.^[8] The M1857 Napoleon fired a cannonball or canister shot at a speed of 1,440 feet per second (or 439 meters per second).^[4] The barrel had a bore of 4.62 inches (117 mm) in diameter and was 62 inches (1,600 mm) long.^[4] The barrel alone weighed 1,220 pounds (550 kg).^[4] With its gun carriage it weighed 2,445 pounds (1,109 kg) and was pulled by a team of six horses.^[6] The average gun crew was six men.^[6]

• 12-Pound Napoleon Cannon on YouTube