The fact that Wisky drove off a massive British Fleet means that the Battleships will be created for sure. They can see a Battleship in RL. They ain't seen an Aircraft Carrier.If they have enough fuel,then ramming british ships without firing guns would be better option.
3 months - that enough to change History permanently.If they leave blueprints for technology,then - USA rules from,let say,1850,not 1945.
Probably,considering that with 1812 tech it is easier to build 1920 plane then 1920 battleship,they would start with carriers and do not bother with battleships at all.