so, south carolina militia units, should they want to attack the u.s. army, are going to have to cross a mile of water first. right now we are standing outside of the sally port, or the entrance, to fort sumter, and what we are standing on is the granite wharf. and this is where anderson and his men would have landed on the night of december 26, 1860. >> for more than three months, anderson and his men peaceably held the fort. then on april 12th, the confederate general beauregard gave the command to open fire. [ cannons firing, mortars exploding ] this is one of the weapons the rebs would have used to bomb the fort. >> this is a 10-inch mortar, which is a small cannon. it's usually used -- it has a high trajectory, so it can be used to shoot over the walls of a fortification like fort sumter. and this is the same type of model that would have fired the first shot of the civil war. [ cannon fires, mortar explodes ] so, we're standing inside of a casemate here at fort sumter. a casemate is a gun room, so it just would have had one gun inside of it, and,