I don't think it's a bromeliad - there aren't any native to North America that I am aware of, so someone would have had to plant it there deliberately. I also don't believe there are any varieties that would survive winters unprotected in SC.
That said, I'm not really sure what it is. Superficially it resembles some dracaena, yucca, and/or agave varieties, tho, none of those really seem right, either (especially dracaena), particularly if the plant in question is shade loving. I'm far from an expert in any of these plants, tho.
