Micajah Harpe, born Joshua Harper around 1768 in North Carolina, was of Scottish descent. During the American Revolutionary War, the Harpe family were Loyalists, leading to social ostracism. Micajah and his cousin (or possibly brother) Wiley "Little" Harpe turned to a life of crime, engaging in theft and violence. They later joined a group of Chickamauga Cherokee, adopting some of their customs and tactics. By the late 1790s, the Harpes had become notorious outlaws, feared across the American frontier.

Between 1797 and 1799, Micajah and Wiley Harpe embarked on a brutal killing spree across Tennessee, Kentucky, Illinois, and Mississippi. Their victims included men, women, and children, often murdered without clear motive. The Harpes were known for their extreme cruelty, sometimes disemboweling victims and filling their bodies with stones before disposing of them in rivers. Their crimes were so heinous that even fellow outlaws distanced themselves from the Harpes.

In August 1799, a posse led by Moses Stegall tracked down the Harpes in Kentucky. During the confrontation, Micajah was shot and captured. Before dying, he confessed to numerous murders. Stegall then decapitated Micajah, placing his head on a pole as a warning to others. The location became known as "Harpe's Head."