Congress approved it. The Navy assigned it to three shipyards. Five hull numbers were issued. Five names chosen — Montana, Ohio, Maine, New Hampshire, and Louisiana. The blueprints were completed in full. The steel was being ordered. Not a single piece of it was ever cut. The Montana class was the most powerful battleship the United States ever designed — and it was cancelled on July 21st, 1943, before any of its five hulls had a keel laid. This is the story of why. At 70,000 tons fully loaded, the Montana class would have been heavier than Japan’s Yamato — the largest battleship ever actually built. It would have carried twelve 16-inch guns in four triple turrets, three more than the Iowa class. Its armor belt was designed to withstand its own shells at virtually any combat range — the only American battleship ever built to that standard. And at 121 feet wide, it was too broad to pass t

Source: Facts About the Montana Class — The Most Powerful Battleship America Never Built