Background
He was the son of Nathaniel Barnwell and Mary Gibbes.
He was the son of Nathaniel Barnwell and Mary Gibbes.
During the American Revolution, he served in the South Carolina Provincial Congress (1775–1776) and the first South Carolina General Assembly (1776). As a major in the South Carolina militia during the American Revolutionary War, he was captured at Charlestown in 1780 and was later released in a prisoner exchange. He was appointed a general in the South Carolina militia after the war.
He frequently served in the South Carolina Senate from 1778 until his death.
He was elected to the Confederation Congress in 1784 but did not attend. In 1795, he was elected to the 4th United States Congress but declined to serve.
Other relatives include Robert Woodward Barnwell and Senator Robert Barnwell Rhett.
He was a member of the state convention to ratify the United States Constitution in 1788.