 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.