Wilmot G. de Saussure was born in Charleston, South Carolina on July 23, 1822. His parents were Henry A. de Saussure, a lawyer, and Susan de Saussure. De Saussure graduated from the University of South Carolina in 1840 after two years of study. He then studied law and became a prominent lawyer at Charleston in practice with his father. De Saussure served in the South Carolina House of Representatives of the South Carolina General Assembly in 1848-1849, 1854-1857 and 1860-1863. Wilmot Gibbes de Saussure married Martha Gourdin. When their eldest son, Henry A. de Sassure, died in 1903, two adult sons and three adult daughters survived their brother.
Wilmot Gibbes de Saussure began his Civil War service as a colonel in the 1st South Carolina Artillery Regiment of the 4th Brigade of the South Carolina militia at the siege of Fort Sumter. His force occupied Fort Moultrie when the U.S. Army garrison withdrew to Fort Sumter on December 26, 1861. De Saussure was in command of the Morris Island batteries during the bombardment of Fort Sumter on April 12 through April 14, 1861. In August 1861, de Saussure was appointed a brigadier general in the South Carolina militia and was given command of the 4th Brigade for the remainder of the war. On April 11, 1862, de Saussure was elected adjutant general and inspector general of the South Carolina militia. He also was appointed Secretary of the Treasury of South Carolina in the summer of 1861 by South Carolina GovernorFrancis Pickens. De Saussure commanded a force of militia and Confederate States Army troops during the siege of Charleston in 1863. This force guarded the rear of the city. In late 1864 and early 1865, de Saussure's men were sent to oppose the forces of Union Major General William T. Sherman as they marched through the Carolinas.
Later life
After the war, Wilmot G. de Saussure was a prominent lawyer and was active in civic affairs in Charleston. He wrote several works of South Carolina history. He was president of the Huguenot Society and the Cincinnati Society. He was also president of the St. Andrew's Society, the St. Cecilia Society and the Charleston Library Society. He was a Harbor Commissioner for Charleston and a member of the Chamber of Commerce. De Saussure was a Freemason. He served as a grand master of his lodge from 1873 to 1875. He also was a member of the Odd Fellows. Brother de Saussure served as Grand Sire during the term 1853-1855 - being installed in Philadelphia, PA and presiding in Baltimore, MD. Wilmot Gibbes de Saussure died on February 1, 1886 in Ocala, Florida where he had gone with the hope of restoring his deteriorated health. He is buried in Magnolia Cemetery, Charleston, South Carolina.