One hundred and fifty years ago this week, on February 17, 1864, a Confederate submarine made the first successful attack in history, sinking the USS Housatonic while trying to break the Federal blockade during the Civil War. Like a bee inserting its stinger and then retreating, the H.L. Hunley jammed its explosive into the side of the Yankee ship. When the explosive detonated, the Housatonic sank in five minutes time.
However, the attack wasn’t entirely successful, for the Hunley and its 7-man crew vanished without a trace. The Civil War submarine remained lost until it was raised from the bottom of Charleston Harbor in August of 2000. You can see the ship on display today in Charleston, South Carolina.
My novel, The Lincoln League, includes a subplot about Confederate submarines. I based this subplot on work that was actually going on in Richmond during 1861 and 1862–work on primitive forerunners to the Hunley. These subs usually posed more threat to the crew than to enemy ships.
I can explain how the H.L. Hunley works, but an excellent,  3-minute video by National Geographic does it much better than I could ever manage. As the video says, the Hunley was 50 years ahead of its time, for the next successful submarine attack had to wait until World War I.
National Geographic Video of the H.L. Hunley
By Doug Peterson