Authorized under the 1940 “Two Ocean Navy” building program and funded in the fiscal year of 1941, the U.S. Navy’s Montana-class battleships were envisioned as the successors to the formidable Iowa class. These leviathans of the sea, with a proposed standard displacement of 60,500 tons and armament of twelve 16″/50 caliber guns, were designed to outmatch any battleship afloat, closely rivaling even Japan’s massive Yamato-class in firepower and armor. However, these titans of naval might remained on the drawing board, as the necessities of World War II dictated a paradigm shift from the era of the battleship to the age of the aircraft carrier.
The initiation of the Montana-class battleships coincided with a period of escalating tensions and the anticipation of a global conflict that would inevitably engulf both the Atlantic and Pacific theaters. The Montanas were to be the first U.S. battleships without constraints imposed by the Panama Canal, a design decision that allowed for greater size, armor, and firepower.
Despite the advances in their design, the Montanas were slower than their predecessors, the Iowa class, with a projected maximum speed of 28 knots, and required a beam too wide for the Panama Canal locks. The U.S. Navy had envisioned the Montanas as a powerful counter to Japan’s Yamato and the need for a formidable naval presence in a two-ocean war. However, the attack on Pearl Harbor and subsequent battles such as the Coral Sea and Midway highlighted the increasing dominance of aircraft carriers in naval warfare. The era of ship-to-ship gun battles was giving way to a time where air supremacy and anti-submarine measures were paramount.
By July 1943, the Navy had recognized the shift in naval doctrine and made the decisive move to cancel the Montana class. None of the keels for the five planned ships—Montana (BB-67), Ohio (BB-68), Maine (BB-69), New Hampshire (BB-70), and Louisiana (BB-71)—had been laid.