[2] Located in a rural upland area long devoted to cotton plantations, part of the Black Belt of the South, the county was formed in 1908 from portions of Lexington and Orangeburg counties.

Calhoun County is part of the Columbia, SC Metropolitan Statistical Area.

It has an overall score of 52 including factors health, crime, equity, education, and housing.

[5] During the American Revolutionary War, Calhoun County was home to the famous Siege of Fort Motte.

[6] In 2011, an illegal dumping of an estimated 250,000 vehicle tires was discovered in Calhoun County near Elloree.

Astonishing biodiversity exists in Congaree National Park, the largest intact expanse of old growth bottomland hardwood forest remaining in the southeastern United States.

Waters from the Congaree and Wateree Rivers sweep through the floodplain, carrying nutrients and sediments that nourish and rejuvenate this ecosystem and support the growth of national and state champion trees.

[11] Although the park lies outside the boundaries of Calhoun County, much of the environment is similar.

Calhoun County is part of the evacuation route for hurricanes and coastal flooding.

Between 2016 and 2017 the population of Calhoun County declined from 14,886 to 14,808, a -0.524% decrease and its median household income grew from $42,779 to $44,010, a 2.88% increase.

The population of Calhoun County is 53.6% White Alone, 41.6% Black or African American Alone, and 3.58% Hispanic or Latino.

[26] Other elected positions in the county are Sheriff, Auditor, Coroner, Treasurer, and Clerk of Court.

It was built about 1877, and is a one-story, medium-gabled white clapboard structure in the Greek Revival style.

Although much of Calhoun County is rural, there are many factories including Devro, a UK company that makes sausage casings.

[28] Other factories include Starbucks (Roasting Facility), DAK Americas, Zeus Industrial Products, Fitts Co Inc, and Thermo King Columbia, Inc.

[33] As of April 2024[update], some of the largest employers in the county include Devro and Starbucks.