The four pieces of heavy artillery now standing in silent guard over Capitol Square are not merely symbolic protectors, but actual pieces of armament produced during the Civil War and intended for use in that conflict.

The tradition of having artillery pieces on display in public areas is a very old one, and before these Civil War cannons adorned the grounds there were several cannons brought out of storage at the Ohio Arsenal and displayed on the Statehouse lawn. An 1881 newspaper article states that these guns, trophies of the Mexican War, were "a great curiosity, they being very much behind the times."

On display at each of the corners of the Statehouse are four cannons, two six pounders and two 12 pounders. The cannons are made of bronze and have smooth bores. All four of these guns were created in the Cincinnati foundry of Miles Greenwood in 1864, and though intended for active service, by the time of their completion much of the war was over. The term "pounder" refers to the maximum weight of the projectile each could fire. A so-called 12 pounder, also referred to as a "Napoleon", could send a twelve pound object up to 6,000 feet, making them effective weapons for offensive and defensive operations.

All four of these guns were extensively restored in 1995. While the bronze cannon barrels themselves are totally original, the wooden carriages they rest upon are new work. They are completely useable and are often fired for ceremonial and educational events.