How did they form? What are their specific traits? Stereotypes (even untrue, if marked as such)?
If cultural differences coincide with geography, please mention in, too.
In the questions about weird things people from different continents do somebody pointed out, that Europeans have little knowledge of this, so please fix my ignorance.
Found the East Coast guy lol
I would never think to break out Mid-Atlantic into its own thing, and I would never think to combine California and the Pacific Northwest.
Just shows how regional bias plays into what you think of as "cultural regions".
I'm in the west.