Would a Sixth Battle Squadron have changed Jutland?
Short answerBritish pre-dreadnoughts would slow the line, but five additional American dreadnoughts would raise the Grand Fleet to an overwhelming 42 modern capital ships against 27 German dreadnoughts and pre-dreadnoughts.
NotesA squadron of Lord Nelson, Duncan, and related pre-dreadnoughts would constrain Grand Fleet speed and add little useful power. The American Sixth Battle Squadron is a different proposition: five extra dreadnoughts could lift the British total to 33 battleships and nine battlecruisers. That would turn an already strong superiority into an extreme one, even if the U.S. ships were not tactically transformative individually.