As you know, Ft. Sumter was the birthplace of the Civil War, and for about $20 a person you can take a boat-ride out to Ft. Sumter and see the fort and pretend you're a yankee firing on those ungrateful southerners. Or, you can pretend to be a rebel warrior, protecting your homeland from those yankee carpetbaggers.
Whatever your fancy, you'll sure have fun at Ft. Sumter. The grounds are kind of creepy because there's dark crumbling nooks here and there.
They say you'll have bad luck if you take any of the rock wall with you---I don't know if it's true. I think they tell you that so that 10,000,000 tourists a year don't take 10,000,000 peices of the rock wall because if that happeend, there would be no more Fort. But still. Don't take the rock wall or any other artifacts you find. Give them to the helpful people that work there so that they can put them in the museum on site and charge admission for YOU to see the nail YOU found.