It entirely depends on what kind of establishment

I assume I would recieves a cup of tea.

They always ask "you mean hot tea?" And I fill with rage and think YES, of course I bloody well want my tea to be hot!

If I asked for just "tea" at a restaurant here in the central valley of California, I would be asked what kind. The choices would be unsweetened ice, sweetened ice, or Lipton Raspberry Brisk (or a knock off brand I always forget the name of that's becoming more common than the Lipton). The only restaurants I know of that Incan get hot tea are Chinese places, and they usually only have oolong tea.

Either you'll get a sweet iced tea, or they'll ask "sweet or unsweet" before bringing iced tea.

Durham, North Carolina here.

In the Texas, you can ask for “half and half” tea. You’ll get a mixture of sweet and unsweet iced tea. In a huge glass with plenty of ice. And free refills.

If you want hot tea, you need to ask for hot tea. Most places will bring you a couple selections of bagged tea and a too-small pot of not-hot-enough water. Hotel restaurants are known for bringing out a huge caddy of various tea bags for you to chose from. If you want milk/cream in your hot tea, you’ll have to ask for it, it’s not assumed.

Southern CA default seems to be unsweetened iced tea, which is basically all I drink so it's fine with me.

You ask for iced or hot, and you usually get some nasty ass Lipton tea if you go for hot, though this may vary by restaurant. I love tea, but I've spoiled myself with fancier ones to the point where I can't stand most of those big American brands. Some iced teas I can at least tolerate though.

From merica, Pacific Northwest. My experience is hot you'll get some hot water in a kettle with a box of various teas, or iced which is non sweetened, can add sugar if ya want. If I just said "tea", they'd ask hot or iced. Id feel strange just saying "tea" without being more specific.

NM here and it depends on the restaurant, many only have iced tea. But when you ask for tea you will be asked if you wanted sweet or unsweetened. If you say sweet, they bring you packets of sugar and a glass of unsweetened tea.

Fast food places will have both dispensers but mostly the sweet is unsweetened.

I dunno, I'm southern, and you're right that sweet iced black tea is the default anywhere below the Mason-Dixon line. The only real difference you'll run into outside of niche places is Lipton vs tetley vs whatever industrial food supply had.

But you can get unsweetened almost anywhere, and Chinese-American places will almost always ask if you want sweetea just to be sure.

Above the line, when I've traveled into damn yankee land over the years, it's changed. Back as a kid driving through the Albanians Appalachians up to Ohio, and Pennsylvania, once you got into west Virginia, it was a coin flip what you'd get between sweet and not, and anywhere north of that, it was unsweetened iced tea.

Last trip I took, sweet iced was default even in Pittsburgh and Philadelphia, the few restaurants we went to.

I remember going to DC on a school trip in jr high though, and McDonald's didn't have tea at all in the one we went to. Baltimore during the same late eighties era, I only went a couple of times, but the fast food places didn't have tea on the menu.

Now, all of that could have just been a matter of not going to the right places, of course. But it's what I experienced.

Around here, in the Appalachians down to the foothills, good luck getting unsweetened iced tea. My wife is a damn yankee that likes her iced tea fairly strong, but only a tiny bit sweet. She calls the extra dark and sweet we have in this area tea syrup lol.