Looking in from the outside, US culture is substantially less homogenous than Australian culture.

Cultural variety arises from isolation. The US was founded sufficiently long ago that there was time for each region to establish distinct cultural flavours, in no small part contributed by waves of immigration being unevenly spread throughout the country.

From my experience of meeting US citzens, even outside North America, it's fairly normal to get something like "Ohio", "Pensilvania" or "Wisconsin" when asking where they come from, as if I'd _of course_ know where those places are (I do).

Unless you're from Mississippi raises hand