[5] It is named for Francis Marion, a brigadier general from South Carolina in the American Revolutionary War.

[6] Some sixty years after the first permanent settlement in South Carolina, a group of English settlers sent out by the Lords Proprietor landed in Georgetown and moved up the Pee Dee River to the junction of the Little Pee Dee River about halfway between Georgetown and the present town of Marion.

When Craven was divided, this segment of land was placed in Georgetown District and was known as Gilesboro after Colonel Hugh Giles, an American Revolutionary war hero who fought under Francis Marion.

On December 17, 1847, when by an act of the South Carolina Legislature a charter was issued to the town, its official name was given as "Marion".

The name honors General Francis Marion, a hero of the Revolutionary War.

[7] A commission was appointed by the South Carolina Legislature to locate the site for a court house.

The court house was not complete, so it was held in a log building on Colonel Hugh Giles' plantation about two miles below Marion.

The Commissioners appointed to select the site for the Court House were offered land by several land owners in the vicinity, including Giles, but they chose and accepted four acres from Thomas Godbold, a grandson of Captain John Godbold.

Before the end of the war, most of the Loyalists had pledged allegiance to the colonists due to the activities of General Francis Marion in the area.

The Revolutionary battles in the county were Port's Ferry, Blue Savannah and Bowling Green.

During the American Civil War, Marion County was spared damage from Sherman's troops due to the Big Pee Dee River being at flood stage.

Gen. W.W. Harllee was the first president of the railroad; the town of Florence, to the west of Marion, was named for his daughter.

[8] According to the United States Census Bureau, the city has a total area of 4.3 square miles (11 km2), all of it land.