Brutus De Villeroi's prototype design for the Union submarine Alligator, artist's impression

Brutus De Villeroi's prototype design for the Union submarine Alligator, artist's impression
Scanned by
  National Oceanic and Atmospheric Administration
Image type
  engraving
Courtesy of
  Historique de la Marine/National Oceanic and Atmospheric Administration
Source citation: 
Historique de la Marine/National Oceanic and Atmospheric Administration
Source note
 
The Alligator, though accepted officially by the U.S. Navy, was never commissioned and therefore does not carry the prefix "U.S.S."