In planning a new battleship class in the 1930s, the US Navy was heavily constrained by international treaty limitations, which included a requirement that all new capital ships have a standard displacement of under 35,000 LT (35,600 t). This restriction meant that the navy could not construct a ship with the firepower, armor, and speed that they desired, and the balancing uncertainty that resulted meant that the navy considered fifty widely varying designs.
Eventually, the General Board of the United States Navy declared its preference for a battleship with a speed of 30 knots (56 km/h; 35 mph), faster than any in US service, with a main battery of nine 14-inch (356 mm)/50 caliber Mark B guns. The board believed that these ships would be balanced enough to effectively take on a multitude of roles. 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 27-knot (50 km/h; 31 mph) 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 prioritized firepower at the cost of speed and protection. After construction had begun, the United States invoked a so-called "escalator clause" in the international treaty to increase the class' main armament to nine 16-inch (406 mm)/45 caliber Mark 6 guns.
Both North Carolina and Washington saw extensive service during the Second World War in a variety of roles, primarily in the Pacific Theater where they escorted fast carrier task forces, such as during the Battle of the Philippine Sea, and conducted shore bombardments. Washington also participated in a surface engagement, the Naval Battle of Guadalcanal, where its radar-directed main batteries fatally damaged the Japanese battleship Kirishima. Both battleships were damaged during the war, with North Carolina taking a torpedo hit in 1942 and Washington colliding with Indiana in 1944. After the end of the war, both ships remained in commission for a brief time before being laid up in reserve. In the early 1960s, North Carolina was sold to the state of North Carolina as a museum ship, and Washington was broken up for scrap.
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