Here's another idea I've no idea if it's been done before, but here it is if people are interested...
The challange here is to make George Washington turn into a more ruthless, dictatorial and "Robespierre-esque" post-revolutionary leader of the USA. He could be reluctantly forced down the path of toitalitariansim by events (danger of counter-revolution or bigger global efforts to restore British rule over the colonies etc) or simply have him determined to go down that path from the start.
Feel free to add any number of variants and take the timeline right up to current day, if this is OK with the forum (what sort of USA would we have today had Washingotn been a dicator? Would it still be a dictatorship or would it have since mellowed-out as France did?).