Towards the end of this lengthy design period the General Board of the United States Navy declared its preference for a battleship with a speed of , faster than any in US service or under construction, with a main battery of nine /50 caliber Mark B guns. The board believed that such ships could fulfill a multitude of roles, as they would have enough protection to be put into a battle line while also having enough speed to escort aircraft carriers or engage in commerce raiding. However, the acting Secretary of the Navy authorized a modified version of a different design, which in its original form had been rejected by the General Board. This called for a ship with twelve 14-inch guns in quadruple turrets and protection against guns of the same caliber. In a major departure from traditional American design practices, this design accepted lower speed and protection in exchange for maximum firepower. After construction had begun, the United States became concerned over Japan's refusal to commit to the caliber limit of the Second London Naval Treaty, so they invoked the "escalator clause" of that pact and increased the class' main armament to nine /45 caliber Mark 6 guns from the original twelve 14-inch guns.