Maple Leaf (shipwreck)

Maple Leaf is a United States National Historic Landmark in Jacksonville, Florida, United States. "Maple Leaf", a side paddlewheel steamship, was first launched as a freight and passenger vessel from the Marine Railway Yard in Kingston, Upper Canada in 1851. The sidewheel paddle steamer measured at the beam.
Sinking.
"Maple Leaf" was a civilian merchant steamship, chartered as a transport by the Union Army during American Civil War, that struck a Confederate torpedo - what we would now call a mine - as she was crossing the St. Johns River near Jacksonville on April 1, 1864. Four crew members lost their lives in the sinking. This was the first mine casualty of the war. The screw steamer was dispatched to assess the condition of the wreck on April 2, and Captain Henry W. Dale concluded his ship and cargo as a total loss.
Wreck.
"Maple Leaf"′s wreck site is located in the St. Johns River, to the west of the adjacent Mandarin neighborhood, in southeastern Duval County. The wreck was deemed a threat to river navigation so the U.S. Army Corps of Engineers had all structural components above the ship's main deck removed to clear the channel in the 1880s. The shipwreck was rediscovered by the St. Johns Archaeological Expeditions, Inc. in 1984. Volunteers identified the wreck in 1984. The shipwreck site has been given the Smithsonial trinomial 8DU8032.
Because of the wreck's remarkable state of preservation (down to the line cleared in the 1880s), it is the most significant Civil War-era shipwrecks yet discovered, and a good example of a mid-19th century Great Lakes steamer. On October 12, 1994, it was designated a National Historic Landmark.