McCormick County and its county seat, the town of McCormick, were named for inventor Cyrus Hall McCormick (1809-1884). The county was formed in 1916 from parts of Edgefield, Abbeville, and Greenwood counties.
This area was settled in the mid-eighteenth century by Scotch-Irish, French Huguenot, and German farmers. Some of the early inhabitants were massacred by Cherokee Indians at Long Cane in 1760, and the British subsequently built Fort Charlotte to protect the region; this fort was one of the first seized by the Americans in the Revolutionary War.
About 1850 gold was discovered where the town of McCormick now stands. The Dorn Gold Mine, which later also produced manganese, was bought by Cyrus McCormick in 1869; he donated land for the town, which was named for him in 1882. This mine continued to operate until the 1930s. Several prominent South Carolinians have resided in the area that is now McCormick County, including governor and U. S. senator George McDuffie (1790-1851), Unionist leader James Louis Petigru (1789-1863), and Moses Waddel (1770-1840), who taught many of the future leaders of the state at his Willington Academy.