Since the late 20th century, the dam's generation of hydroelectric power has also stimulated economic development and industry in the region.

During the Civil Rights Movement, Clarendon County was the site of the Briggs v. Elliott trial challenging segregation of public schools.

This case was one of five combined with what came to be known as Brown v. Board of Education, under which the United States Supreme Court ruled in 1954 that racial segregation of public schools was unconstitutional.

[4] 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.

But due to the development of the railroads in the mid-1800s and construction linking major markets, the canal was superseded and ended operations some years later.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.

Captain Burgess deeded six acres to the state, providing sites for the courthouse and jail, in addition to streets 75-feet-wide on four sides.

The county recovered slowly from the Civil War due to its reliance on agriculture, which suffered a long depression.

Lumber and related mills and industries became increasingly important, with towns developed along railroad lines in the area.

In November 1941, Lake Marion was created as a reservoir by construction of the Santee Dam by the United States Corps of Engineers.

The dam was built across the Santee River to generate hydroelectric power for rural electrification, one of the major infrastructure projects initiated under President Franklin D. Roosevelt's New Deal federal investments during the Great Depression.

This was concluded in law by the United States Supreme Court ruling in Brown v. Board of Education (1954), which declared that separate but equal schools were unconstitutional.

[6] Clarendon Country is located in the east-central portion of South Carolina, inland of the Lowcountry and bordering the southern edge of the Pee Dee.

In part these declines reflected the Great Migration of African Americans out of the South, to seek better jobs, education and living opportunities.

There is a higher percentage of elderly, aged 65 and older, in Clarendon County in comparison to South Carolina, 17.6% and 14.1%, respectively.

However, after Jimmy Carter swept the Deep South and Clarendon in 1976, the county became a Democratic stronghold once again but by much narrower margins than at the beginning of the century, consistently hovering above the 50% marker by only a handful of digits until the 2020 election when Republican candidate Donald Trump became the first Republican candidate to win the county since Richard Nixon in 1972 by a narrow 111 vote margin.

In 2008 the systems had the following pumpage rates, in millions of gallons per day:[27] From boating, fishing, hiking and hunting, to golf on some of the world’s finest courses, Clarendon offers outdoor enthusiasts a buffet of things to do.

Several sporting clay operations and gun ranges are located throughout the county, as well as hunting preserves devoted to providing hunters a controlled environment.