According to the March 18th Brooklyn Daily Eagle, back in the last half of the 19th century, the Commodore Perry and Commodore Barney which operated ferry service between Brooklyn and Manhattan had been the Union Navy during the Civil War patrolling Carolina waters searching for blockade runners.
They were painted black, fitted with cannons and sheathed in metal.
Actually, I believe their use came from being double-enders which could change direction without turning, a very handy thing to be able to do in the narrow and shallow rivers.
Both ships operated until the 1890s.
Chased by a Ferry Boat. --B-R
The Battle of Fort Fisher, N.C.
