The USN certainly had a lot of heavy metal on the books at the start of WW2. Admittedly most of it was left in a re-conditioned burning state after the Pearl Harbour attack (rebuilding if not sunk), but the pre-war building program brought on stream some very useful battlewagons in 1942-43, critical certainly for Guadalcanal operations (see below, Pearl Harbour "targets" left and being the "pre-war new design stream" as in the North Carolina [2] and South Dakota [4] classes [and a hypothetical USS Montana] on teh right):
Late 1943-144 the "new breed" of Iowa class ships started arriving, along with the rebuilt boys who had caught it at Pearl Harbour (see below, column one being the Pearl Harbour and Atlantic Fleet, column two being the "reconstructed" Pearl Harbour battleships [the ships serving in the Atlantic avoided this indignity], column three being the "pre-war new design stream" as in the North Carolina [2] and South Dakota [4] classes [and a hypothetical USS Montana] and finally column four the scary 16" Iowa Class [4] and Alaska [2] large cruiser/battlecruisers):
This is a phenomenal industrial ship building production rate (something the IJN could not think of matching), considering it was alongside the construction of the Essex class fleet aircraft carriers (a total of seventeen during the war and seven more shortly after in late 1940's) and there was also the ten Independence light aircraft carriers. Build baby build was obviously the US motto!