A Secret Confederate Submarine Was So Deadly, Even the Crew Wasn't Safe

1864 painting of the H. L. Hunley by Conrad Wise Chapman. (Credit: Wikimedia Commons) On Feb. 17, 1864, naval warfare was changed forever. That night aboard the U.S.S. Housatonic, master John H. Crosby of the Union Navy saw what he described as a porpoise sliding through the water on a direct course for his vessel just a few hundred feet away. Three years prior, President Abraham Lincoln had ordered a blockade of all major Confederate ports, and the Housatonic, a sloop-of-war with 12 large cannons, was stationed in South Carolina’s Charleston Harbor to help the president apply a stranglehold to the South. Lincoln’s plan was working, and the Confederacy was desperate to smash the blockade and bring in badly needed supplies. But the agrarian South could never hope to defeat the well-equipped, powerful Union Navy using traditional battle tactics. They needed a secret weapon, and that’s exactly what Crosby saw coming toward him that night.