On a ledge 40 feet above the Mississippi, Confederates in March, 1863, laid out Fort Cobun. Protected by a parapet nearly 40 feet thick were four big guns manned by Company A, 1st Louisiana Heavy Artillery. Under the command of Captain John B. Grayson, the guns of Fort Cobun fired their first hostile shots on March 31 at Admiral David G. Farragut’s squadron as it passed downriver. On April 29, seven of Admiral David D. Porter’s gunboats attacked the Grand Gulf fortifications. For more than five hours, the Union ironclads and the guns of Fort Cobun dueled, and the Confederate artillerists disabled the Tuscumbia. Unable to knock out the Confederate guns, the Union gunboats broke off the bombardment. Following the occupation of Grand Gulf, Admiral Porter said, “Grand Gulf is the strongest place on the Mississippi.”