In 1861 Richard Jordan Gatling, a trained dentist from North Carolina, produced an effective mechanical gun. The Gatling Gun consisted of six barrels mounted in a revolving frame. The United States Army purchased these guns in 1865 and over the next few years most major armies in Europe obtained this gun.

The success of Gatling's automatic gun encouraged others to enter the market. In 1879 the Gardner Machine Gun was demonstrated for the first time. A two-barrelled weapon operated by crank which loaded and fired each barrel in turn. The feed system was a grooved strip into which the rims of a box of cartridges could be slid, after which the box was removed. In public trials the gun fired 10,000 rounds in 27 minutes. This impressed military leaders from Britain and the following year the British Army purchased the gun.