What is the name of the submarine used during the Civil War?

The first submarine to be used as an instrument of war was an egg-shaped craft that carried only one person. Four submersible vessels were built during the American Civil War by the fleet. In 1864, a confederate submarine, the Hunley, blew up the USS Housatonic in Charleston, South Carolina, harbor, but the explosion too destroyed itself. Submarines were used in different types of ways. For example, the 'Davids' , did score some successes but their cost was exorbitant; two warships sunk and a third damaged for the loss of two submersibles.