The Gatling gun is known as the forerunner of the modern machine gun. This is a rapid fire gun and was invented by Richard Gatling when it was first used in America Civil War in the 1860s. This gun operation revolves around a cyclic multi-barrel design which facilitates cooling and synchronised the firing-reloading sequence. The first Gatling gun was capable of firing continuously, but it required a person to crank it. The Maxim gun was the first automatic gun in true meaning.