A privately owned vessel that is commissioned by one power to attack merchant ships from a hostile power. The term also refers to the commander or a crew member of such a vessel.
A privateer was commissioned by the issuance of a letter of MARQUE AND REPRISAL to commit hostile acts at sea, generally in accordance with the RULES OF WAR. Letters of marque and reprisal were issued by a state to its own subjects as well as to the subjects of neutral states. The owner of a vessel who accepted letters of marque from both belligerents was, however, deemed a pirate.
Privateering was abolished on an international scale with the ratification of the Declaration of Paris in 1856, which was signed by Great Britain, France, Turkey, Sardinia, Austria, Prussia, and Russia. The United States, Spain, Mexico, and Venezuela, however, did not consent to the declaration. The United States refused to join the treaty because the U.S. Constitution, which gives Congress the power to issue letters of marque, does not authorize it to participate in a permanent treaty abolishing privateering. Regardless, the act of privateering is considered a federal offense punishable by fine or imprisonment (18 U.S.C.A. § 1654 ).
Woodruff, James J. 2002. "Merchants, Traders, and Pirates: The Birth of the Admiralty Clause." Tulane Maritime Law Journal 563.