On 16 October 1916, BB-39, the USS Arizona, named for the newest state in the Union, was commissioned at Brooklyn Naval Yard in New York City. She was the second and last of the Pennsylvania class “super dreadnoughts”.

Battleship technology was rapidly improving in the decade of the First World War, but the US Navy wanted a “standard type battleship” with similar characteristics to simplify operations. The first class of these super dreadnoughts, the Nevada, set the template for battleships as we think of them today: four turrets split by a central superstructure, moderate speed, oil fueled, long cruising range, extreme gunnery ranges, and an “All or Nothing” armor concept. From 1912-1918, five classes of thirteen ships were constructed and they formed the backbone of the US Navy for twenty years. The Arizona was the second ship of the second class, number four of thirteen.

The biggest flaw of the old ironclads and eventually the Dreadnought class of battleships was the relatively uniform armor across the ship. As the ships got larger, the armor got thinner, but heavier. Something had to give. Battle experience had shown that ships could survive being hit in non-critical areas such as berths, administration, galleys etc, but a hit to the fire control, engine, ammunition, propellant etc greatly degraded if not destroyed the ship. The All or Nothing concept put these essential, and very vulnerable, areas in a central heavily armored “citadel” (the “All”) and minimal armor on everything else (the “nothing”). This saved weight and subsequently increased the armor of the citadel. The compact citadel and turrets had the vast majority of the armor which made the Standard type battleships very survivable. The enemy armor piercing shells that didn’t hit the citadel or turrets flew through the ship’s non battle essential areas usually without exploding. The Nevada class was the first class of battleship to incorporate the All or Nothing concept and the Pennsylvania class improved on it. The concept was confirmed at the recent Battle of Jutland. When the Arizona was launched, her citadel was impervious to the 14” shells of the largest guns in that engagement.

The Arizona and her sisters didn’t see action during the First World War due to an oil crisis, but because of the Washington Naval Treaty of 1922, they were essential to the US foreign policy in the inter war years. The Arizona was the flagship of Battleship Division One and represented American interests in the Mediterranean and Caribbean in the 1920s. In 1928, she was transferred to the Pacific Fleet and became the centerpiece of War Plan Orange, the on-the-shelf US Pacific campaign against a potentially belligerent Japan.

In mid-October 1941, almost exactly 25 years after her commission, the Arizona led the Pacific fleet to sea from its peacetime headquarters at San Diego. Due to a breakdown in the negotiations with an increasingly aggressive and militaristic Japan, the American Pacific Fleet sailed as a show of force to its new anchorage on the big island of Oahu, Hawaii, at Pearl Harbor.