S.C. Code Ann. § 58-17-2010: Exceptions as to uniformity in freight charges.

Nothing in the General Railroad Law shall apply to the carriage, receiving, storing, handling or forwarding of property carried for the United States, or any state thereof, at lower rates of freight and charges than for the general public or to the transportation of articles free or at reduced rates of freight for charitable purposes or to or from public fairs or expositions for exhibition.