On November 7, 1861, Union forces attacked Confederates at Fort Walker on Hilton Head Island and Fort Beauregard at Bay Point in the Battle of Port Royal, using the largest amphibious fleet ever assembled off American shores. The Confederates were quickly defeated, and Hilton Head Island became headquarters for the U.S. Department of the South for the rest of the Civil War. The next day, Captain S.F. Dupont reported to Secretary of the Navy Gideon Welles that he had attacked the batteries of Forts Walker and Beauregard, silenced them after four hours of fighting, and driven away the squadron of rebel steamers under Commander Tatnall. Union sailor William H. Fitzhugh, recorded in navy records as a first-class boy, was one of the first casualties at Fortress Monroe in Virginia; he was wounded aboard the Pawnee, died the next day, and was buried with full military honors along with other fallen sailors. Free and formerly enslaved black men served with distinction in the Union Navy, made up about fifteen percent of enlisted men by the close of the Civil War in 1865, and many joined on Hilton Head Island, where their knowledge of local waterways was especially useful to the military.