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.
Colorado here, and at most restaurants you’ll usually be asked what type of tea or be brought a mug/teapot of hot water and an assortment of tea bags to choose from.