Question: Which U.S. Navy battleship was to be the second in its class but had its construction cancelled before the keel was laid?

Related documents: [0]  [DOC] USS "Kentucky" (BB-66) was an uncompleted battleship originally intended to be the second ship of the "Montana" class . However, the U.S. Navy's experiences in World War II led it to conclude that rather than more battleships larger and more heavily armed than the "Iowa" class , it needed more fast battleships of that class to escort the new "Essex"-class aircraft carrier s being built. As a result, hull BB-66 was reordered as an "Iowa"-class battleship midway through the war. [END] 
[1]  [DOC] The "Montana"-class battleships of the United States Navy were planned as successors to the "Iowa" class , being slower but larger, better armored, and having superior firepower. Five were approved for construction during World War II, but changes in wartime building priorities resulted in their cancellation in favor of the "Essex"-class aircraft carrier and "Iowa" class before any "Montana"-class keels were laid. [END]  
Answer: USS "Kentucky"
USS "Kentucky"