The tricky part is that no matter what you do about mentality, a country that big can't be governed centrally before modern means of communication. Initially, it's just going to be rather decentral by default-- even if you call the relevant polities "provinces" instead of "states". The best bet is to discredit the whole Anti-Federalist Movement early on, though. Have the whole clash between centralists and decentralists escalate beyond OTL's proportions. Still, you run the risk that the states will balk if a plan to reduce them to mere provinces is proposed.
Here's a sugestion: have the war of independence drag on longer, or have the economic turmoil caused by it somehow worsened significantly. Mutinies, tax rebellions, etc. break out all over the place. The army is never demobilised, and used to subdue the various insurrectionist mobs. Federalists call for a much stronger government. Anti-Federalists break out into open rebellion against the army. Washington is murdered by an angry mob-- possibly accidentally, in the frenzy. Hamilton - because he's the guy you want for this - becomes the leader of the Nationalist faction. His side wins the internal struggle, which is essentially a civil war. Afterwards, the Nationalists put a Constitution in place the explicitly vests authority in the national government, and reduces the states to mere administrative units (called provinces) that have no actual autonomy or sovereignty.