The CSS Virginia was an American ironclad that was in service with the Confederate States Navy in the mid-19th century. In the American Civil War, the Virginia took part in the historic Battle of Hampton Roads, the first battle between ironclad vessels, when it stood off against the United States Navy USS Monitor.
A painting depicting this battle was stored in the USS Enterprise's library computer in 2254, and was among the materials viewed by the Talosians when they scanned the Enterprise computer. (TOS: "The Cage")
The USS Merrimac, mentioned multiple times in Star Trek: The Next Generation, was christened after the ship's original name as a United States Navy frigate, before its capture by Confederate States armed forces early in the war.
According to the Star Trek Encyclopedia, 4th ed., vol. 2, p. 37, "[That] ship was named in honor of the vessel that became the noted iron-clad warship CSS Virginia, that fought for the Confederacy in the American Civil War." To this very day the vessel remains referred to by citizens of the former Union by its, sometimes misspelled, original name, even if its Confederate service is meant, whereas citizens of the former Confederacy prefer to refer to the vessel by its Confederate name.
In the remastered version of the episode the depiction was replaced by that of the Battle of Fort Hindman. [1]