Interesting build Draco.
The The Vinson-Trammel Act of 1934 and the Naval Act of 1938 effectively authorised significant spending on the modernisation and expansion of the USN to bring it's size up to existing treaty limitations.
The South Dakotas were desinged to the displacement limit of 35,000 tons set by the Second London Naval Treaty of 1936. A so-called "escalator clause" in that treaty combined with the timing of their construction allowed them to be up-gunned from 14" to 16".
The Vinson‐Trammel Act - Dictionary definition of The Vinson‐Trammel Act | Encyclopedia.com: FREE online dictionary
https://en.wikipedia.org/wiki/Naval_Act_of_1938
https://en.wikipedia.org/wiki/Second...n_Naval_Treaty
and links.