Pinckney was 3, his father took the family to Great Britain on colonial business, but the elder Pinckney died in 1758. His mother kept the family in Great Britain, and Pinckney studied at Westminster School, Christ Church, Oxford, and the Middle Temple. Pinckney was admitted to the bar in November 1774 and almost immediately left for South Carolina. Though he had spent the majority of his life in England, Pinckney sympathized with the Patriot cause in the American Revolutionary War. Along with his brother, Charles, he became a captain in the Continental Army in June 1775. After seeing much action, he became an aide-de-camp to General Horatio Gates, and was captured by the British at the disastrous Battle of Camden in 1780. By that time he had married and had an infant child. He was allowed to recuperate from his wounds at his mother-in-law Rebecca Brewton Motte's plantation outside Charleston. In 1781 he and his family traveled to Philadelphia, where he was released by the British in a prisoner exchange. Pinckney returned to the South and that year fought under the Marquis de Lafayette in Virginia. Governor and ambassador After the war, Pinckney focused on his plantations and his legal practice. In 1787, he ran for the position of Governor of South Carolina at the urging of his friend, Edward Rutledge. Pinckney was elected governor with little opposition. He strongly favored ratification of the United States Constitution and presided over the state convention that ratified the Constitution. He served in the South Carolina House of Representatives for St. Philip's and St. Michael's Parish from January 3 to December 20, 1791. Pinckney initially declined appointment to a federal position, but in 1792 he agreed to serve as President George Washington's ambassador to Britain. As Pinckney was unable to get the British to reach an agreement on various issues, including the practice of impressment or the evacuation of British forts in American territory, Washington dispatched John Jay as a special envoy to Britain. Pinckney helped Jay conclude the Jay Treaty, which addressed some issues between the U.S. and Britain but proved divisive in the United States. In 1795, while he continued to serve as the ambassador to Britain, Pinckney was sent to Spain to negotiate a treaty regarding boundaries and U.S. navigation on the Mississippi River. In the resulting Treaty of San Lorenzo, Spain agreed to allow Americans to export goods through