During the Civil War, the U.S.S. Harvest Moon served as the Union Navy's command ship of the South Atlantic Blockading Squadron, whose mission was to prevent the Confederate states from trading with other countries. On March 1, 1865, in Winyah Bay outside Georgetown, the ship struck a torpedo mine and sank to the bottom of the bay in under 20 minutes. All but one crew member survived and were picked up by another vessel. The ship's smokestack can still be seen at low tide.