Born in Effingham County, Georgia, Nathaniel Barnwell was later educated at the University School of Charleston and the University of Virginia, receiving a B.A. and M.A. degree and at the University of Heidelburg, and the University of Grenable, France.
He was admitted to the Bar in 1901 and elected to the South Carolina State Legislature in 1912. During World War I, he served as a Division Judge Advocate and, after attaining the rank of Lieutenant-Colonel, was the Assistant Judge Advocate for the Army Occupation Force.
He was married to Mary Williamson Elliott and had a son who practiced law with him. He served as Chancellor (lawyer) of the Protestant Episcopal Diocese of South Carolina and was a member of the St. Andrews’ Society and the St. George’s Society.
Prominent in civic affairs, he was President of the Chamber of Commerce, Chairman of the Port Utilities Commission, Vice-President of the South Carolina Historical Society, Officer of the Charleston Library Society, and a member of many other civic groups.
In 1936, tuberculosis forced his extended confinement, but upon recovery, he championed the fight against T.B.
A modest gentleman who vaunted not himself, he upheld the profession’s old and high standards and became a lawyer of uncommon attainments.