The American Civil War was the last war in which privately owned warships played a major role. However, the prohibition of privateering under the 1856 Declaration of Paris, combined with the new technologies (ironclading and steam propulsion) and expense of new warships made the practice essentially vanish after the war. Would it have been possible for privateering to have continued without the 1856 Declaration, or were the ships simply too expensive and conflicts requiring their usage too rare for something like a privately owned navy to exist?