Sumner opposed the plan on moral and strategic grounds. In a speech on the Senate floor, he decried the idea that the Union should encourage “privateers” to attack “the commerce of an enemy” with “booty” as the incentive. Even though letters of marque were popular in the past, Sumner noted that European countries increasingly viewed the practice as a barbaric and uncivilized way to conduct naval warfare. He also warned it might provoke Britain’s fearsome navy.
