[3] It is named for Col. Joseph Kershaw (1727–1791), an early settler and American Revolutionary War patriot.

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

The county seat is Camden, the oldest inland city in South Carolina.

This site was settled around 1732 by English traders and farmers who moved inland from Charleston.

At the time, in England and Wales Protestants who were not from the established Anglican church were politically disadvantaged in various ways, however, in South Carolina they could still practice freely (provided that they called their churches "meeting houses.")

Baptists from Abergavenny, Trap, Carmarthenshire, Llanbedr, Crickhowell, Vale of Grwyney, Abertillery, Griffithstown and Brecon arrived in what has since become Kershaw County between 1740 and 1760, primarily arriving as large family units.

After the state seceded from the Union, six men from Kershaw served in the American Civil War as Confederate generals: James Cantey (1818–1873), James Chesnut (1815–1885), John Doby Kennedy (1840–1896), Joseph Brevard Kershaw (1822–1894), and John Bordenave Villepigue (1830–1862), Zachariah C. Deas (1819–1882).

In the last months of the war, Union troops under Gen. William T. Sherman burned parts of Camden in February 1865, in their March to the Sea.

During the Reconstruction era, some freedmen and other men of color were elected to various political offices.

Among them was Henry Cardozo, who had been pastor of Old Bethel Methodist Church in Charleston, South Carolina.

During World War I, two Kershaw County men were awarded the Medal of Honor in two separate actions while fighting in France in October 1918.

The first was Richmond Hobson Hilton, recognized for actions taking place on October 11, 1918, during which he lost an arm.

Statesman and financier Bernard M. Baruch (1870–1965), labor leader Lane Kirkland, and baseball player Larry Doby, the first African-American player in the American League, were each born in Kershaw County.

[25] As of April 2024[update], some of the largest employers in the county include Food Lion, Hengst Automotive, Lowe's, Target, and Walmart.