His father had signed a loyalty oath to the British after they occupied Charleston in 1780 during the American Revolutionary War.

On his death in 1782, the senior Pinckney bequeathed Snee Farm, a plantation outside the city, and the enslavement of numerous people, to his eldest son Charles.

Mary was the daughter of Henry Laurens, a wealthy and politically powerful South Carolina slave trader.

When Charleston fell to the British the following year, Pinckney was captured; he was held as a prisoner until June 1781 and sent north for a potential exchange.

Pinckney and more than 160 men signed oaths of allegiance to the British to avoid having property confiscated.

As a nationalist, he worked in Congress to ensure that the United States would receive navigation rights from Spain to the Mississippi River and to strengthen congressional power.

Pinckney eventually owned several plantations and a townhouse in Charleston in addition to Snee Farm: Frankville and Hopton, situated on both sides of the Congaree River, near Columbia; a plantation in Georgetown consisting of 560 acres of tidal swamp and 600 acres of high land; a tract of 1,200 acres called Lynches Creek; Fee Farm on the Ashepoo River; Shell Hall, a house with four acres of land at Haddrell's Point in Christ Church Parish; a house and garden lot on Meeting Street, Charleston; Wright's Savannah plantation on the Carolina side of the Savannah River; and a tract of land on the Santee River above the canal, including a ferry, called Mount Tacitus.

After Pinckney married Eleanor Laurens in 1788, the elegant three-story brick home at 16 Meeting Street in Charleston presumably became his principal residence.

Although one of the youngest delegates, he later claimed to have been the most influential one and contended he had submitted a draft, known as the Pinckney Plan, that was the basis of the final Constitution.

[2] Pinckney submitted an elaborate form of the Virginia Plan, proposed first by Edmund Randolph; other delegates disregarded it.

[3] Pinckney boasted that he was 24, allowing him to claim distinction as the youngest delegate, but he was 29 years old at the time of the convention.

[4] He attended full-time, spoke often and effectively, contributed to the final draft, and resolved problems that arose during the debates.

The Fugitive Slave Act of 1850 increased requirements on the states and penalties for failure to assist in re-enslavement.

[9][10] Initially introduced as "Nor shall the privilege of the Writ of Habeas Corpus ever be suspended, except in case of rebellion or invasion",[11] it is now a part of Article 1 of the United States Constitution.

The population in the western part of the state was increasing, but legislative apportionment favored the Low Country planters.

In the presidential election of 1800, Pinckney served as Thomas Jefferson's campaign manager in South Carolina.

His daughter married Robert Young Hayne, who became a U.S. Representative, mayor of Charleston, and governor of South Carolina.