Of the vaunted ironclad warships of the US Civil War perhaps the mightiest and most terrifying was the confederate ram Tennessee. On August 5, 1864, she would be put to the test in the largest naval engagement of the war, an engagement that defined the divided loyalties of the War of the Rebellion.
There is legitimate controversy over which ship was America’s first true battleship. But the Navy answers that question relatively clearly- USS Indiana was, from the outset, called "Battleship Number One."