18 U.S.C. § 2116 : US Code - Section 2116: Railway or steamboat post office

Search 18 U.S.C. § 2116 : US Code - Section 2116: Railway or steamboat post office

Whoever, by violence, enters a post-office car, or any part of
any car, steamboat, or vessel, assigned to the use of the mail
service, or willfully or maliciously assaults or interferes with
any postal clerk in the discharge of his duties in connection with
such car, steamboat, vessel, or apartment thereof, shall be fined
under this title or imprisoned not more than three years, or both.