Confederate States of America--History, United States--History--Civil War, 1861-1865, Charleston (S.C.)--History--Civil War, 1861-1865, Confederate States of America--Defenses, United States--History--Civil War, 1861-1865--African Americans, United States--History--Civil War, 1861-1865--Participation, African American, United States--History--Civil War, 1861-1865—Sources, Confederate States of America. Engineer Bureau, Confederate States of America. Engineer Dept, Confederate States of America--History, Military, Confederate States of America—History—Sources✖[remove]7