How Sweet Tea Became The Unofficial Official Drink Of The South
Sweet tea is arguably the most iconic drink of the South. But this mix of black tea, sugar or simple syrup, ice, and garnishes like lemon and mint likely didn't originate in the South — although it's hard to say for sure, as its history is somewhat hazy. A common theory suggests that iced tea actually came from the Northern U.S. Around 1868, iced tea suddenly became a hit, with newspapers in Boston, Chicago, New York, and other cities highlighting it as a trendy drink of the moment.
The reason it came from the North is that this part of the country froze over in winter and that ice would be stored in cold places for use in the summer (bear in mind that electric refrigeration didn't exist at this point). Ice was sometimes transported to the South at this time, but it would have been a serious luxury, and totally unavailable outside of cities. Southerners probably couldn't get their hands on iced tea until the 1920s or later, when the advent of electricity and cars made ice far more easy to access.
When the iced tea trend hit in the 1800s, it was served with lemon, and early recipes only sometimes recommended adding sugar — the first documented reference to sweetened iced tea was around 1878. Tea was grown in the South at this point (near Charleston, South Carolina), but there's not a lot of evidence for anything resembling modern sweet tea being a particular presence until the 20th century.
How it caught on in the South
There are various ideas as to why the sweetened version of tea became such a beloved Southern drink, especially relative to the North, where iced tea probably originated. One theory is that many Baptists and Pentecostals in the South studiously avoided alcohol, so sweet tea filled the gap, helped along by prohibition (although this doesn't exactly explain why sweet tea, rather than iced tea, became popular). Similarly, the fact that the South is blazing hot in summer explains the popularity of iced tea, but not specifically sweet tea.
There are also suggestions that sweet tea evolved as a non-alcoholic alternative to sugary punch-like alcoholic drinks from the South — it probably derived from a punch made from tea. Then there's the idea that both tea and sugar were originally only accessible to elites so some Southerners gravitated toward this status symbol after the Civil War. However, it didn't truly catch on until the 1970s or '80s, when books started to be published on Southern culinary culture, identifying sweet tea as a staple; the fact that sugar was a Southern crop may have helped. It likely caught on slowly over time — yet one more theory is that sweet tea was a positive symbol for Southerners to latch onto, in contrast to negative stereotypes of the South centered around slavery and racism. It's hard to prove which of these is right, though — and there may be a little truth to all of them.