The Model 1841 12 Pounder Mountain Howitzer was a lightweight, scaled down field artillery weapon that was used by both the Union and Confederate armies. Most field artillery in the Civil War was transported by using teams of horses to pull the weapons, but mountain howitzers were designed to be taken apart and the components secured on pack mules for transit. This made it possible to take cannons into mountainous or other terrain that was inaccessible for conventional artillery. On roads, mountain howitzers were harnessed to, and pulled by, a single mule.
Civil War era howitzers were lighter and had shorter length tubes than the longer range, heavier field guns that fired ammunition of the same weight. A weapon was referred to as a certain “pounder” based on the weight of a solid projectile that it was capable of firing. A 12 pounder howitzer had a tube that was 53 inches long and weighed 788 pounds; the carriage for it weighed 900 pounds. A 12 pounder Napoleon smoothbore field gun had a 66 inch long tube that weighed over 1200 pounds and was mounted on an 1100 pound carriage; there were other 12 pounder guns that were even heavier. The 12 pounder mountain howitzer gun tube was about 33 inches long and weighed 220 pounds. The carriage weighed 157 pounds and each wheel was 65 pounds, making the total weight of the mountain howitzer 507 pounds.
A downside to the mountain howitzer compared to other artillery was the limited range of the smaller weapon. At a 5 degree elevation, the mountain howitzer could fire a shell 900 yards; a regular 12 pounder howitzer had a range of about 1070 yards when fired at that same 5 degree elevation. The 12 pounder Napoleon smoothbore had a range of over 1600 yards.
Mountain howitzers usually fired spherical case shot or canister ammunition. Both were shorter range, anti personnel types of ammunition. Case shot was a round hollow metal shell with musket balls and a powder charge inside that had a fuse attached to detonate the powder. Canister was similar to a giant shotgun shell. A mountain howitzer canister shell held 148 .69 caliber musket balls, while a canister shell for a regular 12 pounder cannon held 27 cast iron shot that were nearly an inch and a half in diameter, or over twice the diameter of the shot in the mountain howitzer canister shell. Less often, mountain howitzers would also fire grapeshot and solid shot.
To transport the mountain howitzer, the gun tube was disassembled from the carriage and wheels. The tube was loaded on one mule and the carriage and wheels were loaded on another. Other mules carried the ammunition chests. A gun crew consisted of six men, two to three fewer men than a gun crew for a larger field gun.
Mountain howitzers were used by artillery and infantry units, but their portability made them especially suited for cavalry. They were used in every theatre of operation. Confederates John Hunt Morgan and John S. Mosby both used them in some of their fast moving raids. Union cavalry units used them in mountainous West Virginia; they used them in cavalry raids into the interior of North Carolina from the coast; and they carried them along on expeditions in Kansas, Missouri, and Arkansas where the long distances traveled made other artillery impractical.
Mountain howitzers are not on display at battlefields and in front of small town courthouses as often as the larger artillery pieces are, but there are some that can be viewed today. Three that I have seen are at Fort Scott National Historic Site in Fort Scott, Kansas; at the visitor center at Pea Ridge National Military Park in northwest Arkansas; and at the Wisconsin Veterans Museum in Madison, Wisconsin.