I've been curious to know what the "U.S." would be like today if the American Revolution had failed.

Also, though it's a bit cliche to respond to this question with something like "Hitler is never born", it is interesting to think about just what is necessary to propel a nation into war / dictatorship / evil like that (e.g. just when can you kill / eliminate a single man and succeed in preventing it?) That's something I'm fairly curious about (and the scope of my curiosity isn't necessarily confined to Hitler - could be Bush II, Lincoln, Mao, an Islamic imam whose name I've forgotten, etc.).