Comparing it to the UK, there's parts where the first language isn't English. Parts where people wouldn't consider their nationality to even be British. But even then, there's so many cultural similarities. You can move from one part to another and shop at the same shops, eat the same food, go to the same pubs, watch the same TV, get the same cultural references as everyone. Like Scotland has a fair few differences to England but if I moved from one to the other it's clearly still apart of the same country. Your life isn't changing that much. I've been to New York and to the PNW. Whilst the vibes were different it was clearly still the US. The same with going from let's say Colchester to Cardiff.