18 U.S.C. § 1582 : US Code - Section 1582: Vessels for slave trade

      Whoever, whether as master, factor, or owner, builds, fits out,
    equips, loads, or otherwise prepares or sends away any vessel, in
    any port or place within the United States, or causes such vessel
    to sail from any such port or place, for the purpose of procuring
    any person from any foreign kingdom or country to be transported
    and held, sold, or otherwise disposed of as a slave, or held to
    service or labor, shall be fined under this title or imprisoned not
    more than seven years, or both.