Volley gun
Two notable artillery-sized volley guns were developed in the mid-19th century, although neither was particularly successful in practice. Developed in the 1860s and based on an 1850s design by a captain Fafschamps, the French mitrailleuse is an example of a multi-barreled volley gun that could fire all of its barrels simultaneously or sequentially over a short period of time. Also developed in the 1860s, General Origen Vandenburgh of the New York State Militia designed a weapon that had eighty five parallel .50 caliber rifle barrels. After failing to sell the weapon to the United Kingdom, he reportedly sold a small number to the Confederate States of America, although there is no record that they were actually used. One Vandenburgh gun was located at Fort Fisher, North Carolina, and another reportedly at Salisbury, NC.
Timeline of United States inventions (before 1890)
The machine gun is defined as a "fully automatic" firearm, usually designed to fire rifle cartridges in quick succession from an ammunition belt or large-capacity magazine. The world's first true machine gun, the Maxim gun, was invented in 1884 by the American inventor Hiram Stevens Maxim, who devised a recoil power of the previously fired bullet to reload rather than the crude method of a manually operated, hand-cranked firearm. With the ability to fire 750 rounds per minute, Maxim's other great innovation was the use of water cooling to reduce overheating. Maxim's gun was widely adopted and derivative designs were used on all sides during World War I.