Common in the late 18th century up to the mid 19th century, the musketoon was simply a carbine or short version of a standard infantry musket. The purpose of the musketoon was to create a lighter and more compact musket for cavalry, artillerymen, engineers, and rear echelon troops. Later they were commonly issued as the standard arm of dragoons, a type of mounted infantry who rode horses into battle but dismounted and fought as infantry once in the fray. The musketoon was perfect for dragoons and cavalry, as it could be carried in a saddle scabbard, and due to its shorter size could be reloaded from horseback. It wasn't uncommon for musketoons to be loaded with buckshot rather than a solid bullet, making them more like shotguns than muskets. Large bore musketoons were produced to be used exclusively as shotguns. Due to their similarity with the older blunderbuss, they are often mistaken as such.
Despite its advantages, the musketoon wasn't the perfect weapon. Due to its shorter barrel length, the musketoon had substantially less accuracy, range, and power than the larger service muskets. This was especially true in the age of rifled muskets, as the bullet had less contact with rifling. After the American Civil War most musketoons were retired for breachloading or repeating carbines and revolvers.