Also known as the Colt Peacemaker or Single Action Army (SAA), the Colt Single Action Army handgun is a single action revolver holding 6 rounds of ammunition, that was designed for the US cavalry by Colt's Manufacturing Company and adopted in 1873, and it was perhaps the most prolific pistol of the wild west.

The Colt Single-Action Army Revolver was produced in several forms and many calibers from 1872 to 1940, with production totaling about 350,000 pieces. As its introduction overlap with the settlement of the Wild West, the names "Peacemaker" and "Frontier Six-Shooter" were popularized. Used by legends like Buffalo Bill Cody, Wild Bill Hickock, Pat Garret and Bat Masterson it was also the weapon of choice for settlers in the West during the late 19th century.

Developed from the Henry rifle and the 1866 "Yellow Boy", the 1873 Winchester lever-action repeater achieved fame in the Jimmie Stewart movie "Winchester '73". During its production run, from 1873 to 1919, about 720,000 pieces were made in Winchester's Connecticut factory. The gun was available in several center-fire calibers and its tubular magazine was located underneath the barrel.

The name "Kentucky Rifle" is largely misleading; they were primarily made in Pennsylvania, Maryland and Virginia. The "Kentucky" name came about as a result of the Battle of New Orleans in the war of 1812, which was significantly won by these rifles, in the hands of two thousand frontiersmen from Kentucky. While the design was influenced by the German Jaeger rifles and the slender English and French fowling pieces of the early 18th Century, the Kentucky is uniquely American.