The Coehorn was of Dutch design and credited to its inventor, Dutch officer Baron van Coehoorn in the mid-1670s. It was a mortar weapon typical of the period but managed a long and healthy combat service life. The system relied on indirect-line-of-sight firing and proved effective in displacing dug-in enemy troops - though range was relatively short. Despite its seemingly trainable (elevation) barrel assembly, the weapon basically fired along a fixed trajectory. Its construction made it possible for a team of four men to move it from place to place and keep the enemy honest.
Projectile sizes and effectiveness ultimately varied throughout the list of the Coehorn, based largely on the barrel and powder amounts in play. A timed-fuze delay was used for ultimate detonation of the projectile.
The Coehorn made its way to the fighting of the American Civil War (1861-1865) where it was used by both sides in various calibers: 12-pound and 24-pound forms were noted. The guns were featured at Charleston Harbor, South Carolina, namely at Fort Sumter where the first shots of the conflict were fired.