In the South East, they bring you sweetened (usually far too sweetened for my tastes) iced tea. This is amazingly universal.
I live in NC and have been probing the border for years.
For “nicer” restaurants, the universal sweet tea boundary seems to be precisely at the NC/VA border.
I’m happy to get conviced otherwise but in my 26 years living in Spain, Valencia and Andalucia, that was what I have experienced.