On August 1, I wrote about an engagement July 31-August 1, at Coggins' Point on the James River, Virginia, between a Confederate batteries which sank two Union transports before being engaged with the USS Cimarron in a fierce fight.
I'd never heard of the USS Cimarron, so had to look it up.
From good old Wikipedia.
The original name of the ship was the Cimerone. It was a double-ended steam gunboat, 860 tons, with a battery of six howitzers for river operations and a 100-pdr. rifle cannon for blockade duty.
It was commissioned 5 July 1862, and saw action very soon after that. She was decommissioned 7 August 1865 and sold in November 1865.