Imagine you are standing near the Missouri River on August 19, 1867, taking in the vast landscape surrounding Fort Stevenson. It’s quiet and still from your vantage point in Dakota Territory. Suddenly, almost without warning, the silence is interrupted by the loud blast of a cannon, signaling trouble at the Fort.

The three-inch ordnance rifle cannon had been fired. A band of two or three hundred Indians had been causing trouble in the neighborhood, stealing mules and killing a wagoner. The cannon was powerful. One Indian lost his leg from the first cannon shot, another was wounded, and one of their horses was ripped open from about 1800 yards away, where they thought they were out of firing range. They had seen enough. The Indians fled, largely in part due to the destruction caused by the cannon.

The 3-inch Ordnance rifle was adopted by the United States Army in 1861. This cannon, with a conical projectile that weighed 9.5 pounds, had excellent accuracy at a much longer range than its predecessors. The barrel itself weighed 820 pounds, not hard to believe if you heard its deafening blow. 965 of these cannons were manufactured from 1861 to 1867 at the Phoenix Iron Works in Pennsylvania. Advancements in engineering, along with the conical projectile, gave the cannon its long-range accuracy. The cannon was coupled with a caisson, responsible for carrying two ammunition chests, with 50 rounds in each chest.

After all these years, 350 original 3-inch Ordnance rifles still remain. The Fort Stevenson Guardhouse holds an exact replica of the original which is fired during Frontier Military Days, the loud blast of the cannon signifying the opening and closing of each day.