On this day in 1864, the Confederate submarine Hunley, armed with a torpedo, sank the Union's Navy ship Housatonic off the coast of Charleston, South Carolina. It is considered the first successful attack by a submarine.

It Was a Cold and Quiet Night... just outside Charleston Harbor approximately four miles off Breach Inlet on the moonlit sea. The Union ship Housatonic was anchored there, a lookout standing watch. There had been rumors that the Confederate army had a new secret weapon. But what?

Porpoises, Ho? The lookout saw something move through the water. Was it another porpoise? Floating debris from the wreckage of Fort Sumter?

Meanwhile, Inside the Dolphin... It was no dolphin. It was the cylindrical Hunley ~ a hand powered submarine. Inside the Hunley, eight soldiers sweated over the hand cranks that powered a propeller. The captain manned the dive planes. The Hunley was headed straight for the Housatonic.

Back on the Housatonic... The lookout sounded the alarm. Union soldiers fired at the bizarre floating object. Their bullets ricocheted off the side. The object continued to approach.

3-2-1 Contact. As the H.L. Hunley approached the stern of the Housatonic, it plunged downward, with a harpoon torpedo mounted on an iron shaft extending from the bow. It planted the 135 pound torpedo into the Housatonic's stern. Then the men inside the Hunley back-pedaled, backing their sub out, playing out the 150-foot attached detonation rope.

The Explosion That Changed History. Seconds later, an explosion rang out. The explosion set the USS Housatonic on fire before sending it to the bottom.

On This Day in 1864, the Hunley became the first submarine to sink a ship in battle. A successful submarine attack would not happen again until World War I, more than 50 years later.