During the American Revolutionary War, the Battle of Half Way Swamp was fought in December 1780. That was one of the many Revolutionary battles that took place in the area of Clarendon County. Others in this area were the following battles: Richbourg’s Mill, Nelson’s Ferry, Fort Watson/Santee Indian Mound, and Tearcoat. The Swamp Fox Murals Trail has been established as an historical landmark depicting the American Revolution and General Francis Marion, the "Swamp Fox".
The first European settlers in Clarendon County were ethnic French Huguenots, who traveled by boat up the Santee River. Their ancestors had earlier settled in Charleston after leaving France in the late 17th century to escape religious persecution. Transportation of goods by land was difficult, so canals were constructed to carry boat traffic around rapids in the river. The first notable canal was the Santee Canal, which was constructed in 1793. But due to the development of the railroads in the mid-1800s and construction linking major markets, the canal was superseded and ended operations some years later.
In 1798, the state legislature combined three counties - Clarendon, Claremont, and Salem - to form Sumter District for ease of administration. On December 19, 1855, a legislative act was passed establishing the Clarendon District, with the same boundaries as defined for the county in 1785. During the antebellum period, the county was developed as large plantations to cultivate commodity crops, particularly short-staple cotton, by the labor of enslaved African Americans. Cultivation of this crop was made profitable by development of the cotton gin by Eli Whitney, which made processing more labor-efficient. By the time of the Civil War, the population of the county was majority black.
Sumter County - north
Florence County - northeast
Williamsburg County - east
Berkeley County - southeast
Orangeburg County - southwest
Calhoun County - west