The original Yorktown, CV-5 was sunk at the Battle of Midway. Being the first of its class launched, the two ships that followed, the Enterprise and the Hornet were "Yorktown Class". The Hornet was sunk off Guadalcanal. The Enterprise would survice the war and wa scrapped. The Yorktown that is at Patriots Point in Mount Pleasant is CV-10, a second Yorktown. It was under construction when CV-5 wa sunk and renamed Yorktown. The Essex was the first of this type launched and the other ships, including ships named for the sunken Lexington, would be a key factor in the American victory in the Pacific.
