The Lexington class aircraft carriers, originally designed as battlecruisers, were large aircraft carriers built for the U.S. Navy before World War II. This class included two aircraft carriers: the lead ship USS Lexington CV-2 and her sister ship USS Saratoga CV-3. The USS Lexington CV-2 was used to develop and refine carrier tactics in a series of fleet exercises before World War II. This ship was sunk in the Battle of the Coral Sea in 1942.