[lhorie]

Sure but if you consider that you could say the same about e.g. Moscow/Vladivostok or Sao Paulo/Manaus or Sydney/Perth, it doesn't seem like homogeneity is that unique or impressive of a characteristic for an expansive country. IMHO it's more notable to point out that there's a language barrier between Toronto/Quebec despite them being only a few hours away from each other, a form of heteregenereousness that is also present in many countries in Africa, whereas in the US, there's a relatively high level of homogeneity even taking into account highly international places like Chinatowns because of the melting pot effect.