JJANUARY 15, 1865:
At tne request of Sherman, Rear Admiral Dahlgren of the South Atlantic Blockading Squadron, issued orders to prepare a combined naval and military demonstration before Charleston to draw attention away from Sherman's March through the Carolinas.
Before making it, though, it was necessary to locate and mark numerous obstructions in Charleston Harbor. Orders were issued to the monitors to do this.
That evening, while doing this, the monitor USS Patapsco, Lt. Cmdr. Stephen P. Quackenbush, struck a torpedo (mine) near the entrance of the lower harbor and sank instantly with the loss of 64 officers and men, more than half her crew.
She was the fourth monitor lost in the war, the second due to Confederate torpedoes.
Thereafter, only small boats and tugs were used in the search for obstructions. The objective of the expedition was changed to Bull's Bay, a few miles northeast of Charleston.