Patented by Dr. Richard Jordan Gatling (1818-1903-studied medicine and dentistry) , the Gatling Gun has made its mark in history as one of the earliest rapid-fire weapons to enter into wide-spread use. Consisting of multiple barrels (usually around 10) seated in a pivot to allow for rotation, the Gatling Gun was magazine fed, and fired by manually cranking a handle, rotating the barrels, which were fed with bullets and was capable dis-charged at as much as 1,000 rounds per minute, though this was rarely acheived in practice. The ammunition used by the Gatling Gun tended to range from between .45 in (1 cm) and 1 in (2.5 cm) caliber, and it was not uncommon for buckshot to be used in place of regular ammunition. The barrels could be elevated and depressed using the elevating gear, and could be swung left or right by a hand-spike. The Gatling Gun had a simple fore-sight, allowing for quick yet relatively effective targeting. The early Gatling Gun was incredibly heavy and was often mounted on a carriage often leading officers to regard it as an artillery. It was not until the lighter tripod-mounted Gatling came into use in the 1880's that their full potential was eventually unleashed.

The Gatling Gun has seen service in various conflicts, including the US Civil War (1861-65), and by 1870 it was used world-wide. The French adopted a variation known as the Mitraileuse, which had stationary barrels and a loading plate.

During the early 20th century, experiments were carried out with a Gatling Gun with an electric motor, giving rise to the Vulcan Cannon and later weapons such as the mini-gun.