The Gatling gun transformed warfare.
Prior to Richard J Gatling's invention in the 1860s, rows of infantry would fire four shots a minute from their muskets.
A Gatling gun was capable of 350-400 rounds in 60 seconds. Traditional methods of warfare were rendered obsolete overnight.
Cartridges no longer had to be manually loaded into a barrel, thanks to the Gatling's gravity-based reloading system.
All that was required was the continual turn of a cranking handle.
Gatling patented his machine in 1862, one year into the US civil war (1861-1865).
He touted it to both sides (Gatling himself was a member of the Order of American Knights, an underground group that sympathised with the Confederate cause) yet both the Unionists and the Confederates were slow to see its potential.
Only 12 Gatlings were used in the conflict, all bought privately by forward thinking Unionist Maj. Gen. Benjamin F Butler.
Custer's big mistake
It was after the civil war that it really began to take hold, with US forces using Gatlings to devastating effect during the subsequent Indian wars, where the American army's small numbers in battle were compensated by their deadly weaponry.
General Custer had the opportunity to take a Gatling gun with him to the Battle of Little Bighorn in 1876. He didn't take it.
Problems
The Gatling was not without its problems.
The guns were heavy - they required five men to operate them on the battlefield. And the paper-cased cartridges that were initially used meant the mechanism often jammed.
The second of these issues was solved with the improved 1865 version, which employed copper-cased bullets. Although the 1865 never saw service in the civil war, it was fully adopted by the US army in 1866, a year after the war's end.
Several European countries also employed Gatlings for use in the colonies, and they remained a powerful weapon until superseded by the machine gun in the late 19th century.
Gatling guns at auction
The pioneering nature and importance in the history of warfare of the Gatling gun ensures that original examples are much sought after by collectors today.
The earlier examples command the largest bids, with those which are in fine original condition especially so. An 1876 example sold for $280,000 in 2010.
An 1883 version made by Colt sold for $229,050 earlier this month.
