On the night of February 17, 1864, US Navy sailors aboard the sloop-of-war USS Housatonic were watching the approaches to Charleston Harbor. They were part of the Union Navy's blockade force, which was approaching its third year of operation outside Charleston.
At about 8:45 p.m., Acting Master J.K. Crosby noticed a large semi-submerged object slowly making its way toward the sloop. It was believed to be a porpoise or log, but as the object came closer, its size and metal body made clear that it was a man-made vessel.
The sailors raised the alarm, but the vessel was too close to be hit by the sloop's 12 guns, forcing some of the crew to shoot at it with muskets and pistols.
