The War of 1812: Diplomacy on the High Seas Archives Unbound "In time of war the duties of the State Department have always been expanded. During the War of 1812 Congress authorized the Secretary of State to issue commissions of letters of marque and reprisal to private armed vessels permitting them to "cruise against the enemies of the United States." Source: National Archives (U.S.) and U.S. Department of State Library."