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.

[3] 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.

[4] The screw steamer USS Norwich 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.

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.

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 shipwreck yet discovered, and a good example of a mid-19th century Great Lakes steamer.