In the first ever successful attack by a submarine, the Hunley sinks the USS Housatonic, outside Charleston Harbor. Shortly thereafter, the Hunley, supposedly headed back to Sullivan’s Island, vanished.

In 1970, underwater explorer Lee Spence claimed to have found the wreck. In 1995, a second expedition -- led by Clive Cussler -- said it had found the sunken sub. In 2000, the sub was raised, and it now is undergoing conservation.

The Hunley’s attack on the Housatonic killed five Union sailors. All told, 21 Confederate sailors died in the Hunley’s three sinkings, two during training accidents. The third crew died, after sinking the Housatonic, when the oxygen in their submerged vessel was exhausted, it is theorized.