So true. And this question seems to come up half way between the two states.
The default is unsweetened tea here. If you drive south on I-55 the question gets asked more frequently.
You’re approaching the south if they offer you a choice of sweetened or unsweetened tea. You’re on the outskirts of the south if you can order unsweetened tea even though they don’t advertise it. You’re in the south if they look at you like you ordered a pet hippopotomus if you ask for unsweetened tea.
As I posted many times before, this is the best guide to the economic and cultural regions of North America:
Pretty close to this chart, oddly:
http://graphjam.files.wordpress.com/2008/07/funny-graphs-californians.gif?w=500&h=380
(Religious nutballs + Texas)
I think this linguistic map defines the South pretty well. The places with shared liguistic patterns tend to have shared cultural patterns as well.
Incidentally, I think this map also shows why the South has a cultural cohesiveness that is lacking in the North. (A phenomenon which sometimes seems to mystify our Northern brethren and sistren.)
The one failing of the map is that it doesn’t really offer any analysis of Florida. Luckily there’s a whole General Questions thread on whether Florida is “Southern” and in the context of that thread Doper Bambi Hassenpfeffer has put together a helpful map of cultural patterns in Florida.
Hmm. Let’s try that last link again: Bambi Hassenpfeffer’s cultural map of Florida.
Any state farther down than Illinois or Iowa is a southern state. Illinois and Iowa are the middle states. Oklahoma and lower are the deep south.
They make unsweetened tea?
Who in their right mind would drink it?
Queensland. 
Anywhere approximately within a polygon drawn between Weymouth>Bristol>Oxford>London>Brighton and back to Weymouth
Wouldn’t that be FNQ?
Hmmm. Yes, I do believe you’re right. The SE of that state is Florida.
I was born and raised in Arkansas, and I’m surprised that anybody would consider it anything but Southern. Same goes for Louisiana.
Is diabetes outlawed in the South? If so, I’m moving
I’ll turn it around, I moved from Pennsylvania to western Kentucky when I was a teen. While KY was a “border” state during the civil war, my section was definitely confederate.
The town square features a Confederate soldier memorial and the door to the courthouse, to paraphrase a southern writer, faces defiantly southward.
I was a “Yankee” to my new classmates.
Two years later, I again moved from KY to LA (that’s Lower Alabama 'round those parts), more specifically, the region of Mobile Bay (the incredible, portable, bay).
When my new classmates asked me from where I moved, I was happy to say “Kentucky” since I was no longer a “Yankee”. KY, I thought, was definitely Dixie. My camouflage was complete, thought I.
Nope. I was still a Yankee. Kentucky, to them, was definitely “north”.
Strange ideas from them, they had no idea that Pennsylvania, for example, had rural areas. It was very rural where I lived (about 25 miles east of Pittsburgh). I lived on 3 acres and my neighbor was a full production dairy farmer. They pretty much thought you hit the Mason-Dixon line and it was pavement and penguins until you hit Canada. Most, if asked, also said the Mason-Dixon line was right around the KY/TN border, not hundreds of miles farther north.
We moved into a rental house when we arrived near Mobile. The landlord sent a teen boy over to fertilize the lawn one day. The bags of fertilizer were in the garage.
He walked in and spotted this odd object. It was a big, flat, orange blade on a wooden handle with a matching orange plastic grip on the other side. He held it up and asked my sister (who was near because she thought he was cute) what it was. It was a snow shovel. He had no idea what it was.
My father, in Pennsylvania, said a coworker claimed that one day he was going to tie his snow blower onto his car’s roof and start driving south. The first place he was asked, “What is that?” would be the place he’d retire to. I used to think that was a joke.
I thought one of the requirements for a place to be “Southern”, was to have old men dressed in white suits, who are addressed as 'colonel".
You also need “moon pies” and fanta soda. Grits served with breakfast are also important!
You’re thinking of Europe. In the South we drink Nehi, Dr. Pepper & Co-Cola.
Nah. Moon Pies taste best with RC Cola.
The whole state is in the South: Tennessee, North Caroline (kind of; see comments about Appalacia an the end), South Carolina, Georgia, Alabama, Mississippi, Louisiana.
Part of the state is in the South:
Virginia–most of the state is southern, but definitely not Northern Virginia. I grew up in the Shenandoah Valley and frequently heard Northern Virginia referred to as “occupied Virginia.”
Texas–Houston is definitely southern, as are the areas north and east. Going west, the South ends somewhere on I-10 between Houston and San Antonio. I haven’t travelled far enough south in Texas to know where the South ends, but I think it is south of Corpus Christi. In addition I haven’t spent enough time in Dallas to know if it is southern (life is too short to live in Dallas) but from my brief visits there and the comments of people in Houston about Dallas (ie “yankee Texans”), my impression is that it isn’t considered southern.
Florida–I haven’t spent enough time here to know anything beyond north Florida is southern and south Florida is part of New York (or Cuba).
Oklahoma I’m unsure about, but my impression is at least southeast Oklahoma is southern.
West Virginia and Kentucky are tough to decide–they didn’t secede but had (and have) strong Confederate sympathies. They (along with eastern Tennessee, southwest Virginia and western North Carolina) are definitely Appalacia, and I’m not sure whether to consider that South or its own region.
I noticed a distinct southern sounding accent in Columbus, especially compared to Cleveland.