While doing a little research on the South Carolina barbecue sauce map, I stumbled across the most excellent "A Very Brief History of the Four Types of Barbeque Found In the USA" written by Lake E. High, Jr., President, South Carolina Barbeque Association. It's worth reading in its entirety if you're a barbecue lover or geek, or a Southerner.
Below are a two of my favorite bits on the term "barbeque":
Unfortunately, most Americans who live outside of the South in general and
North and South Carolina in particular, use it as a verb or, if they use it
as a noun, use it incorrectly. Midwesterners or Yankees will say to friends, "I'm going to barbeque some hamburgers tonight." Or they will say, "Let's put some brats on the barbeque and break out some beer." And while everyone will be having a great time sitting around in the smoke, the use of the word in that way is incorrect. That neighbor is going to grill some hamburgers, not barbeque them. The cooker he is going to cook them on should be called a grill, not a barbeque.
[...]
The incorrect use of the term barbeque on television, in movies and in magazines which is, more often than not, written or spoken by people who know nothing about real barbeque, has led to the misconception, for instance, that beef is barbeque. It's not. Don't forget, barbeque is more specifically a noun, a specific thing, and that specific thing is pork, not beef or fish, or beaver, or shrimp or anything else. It's quite possible to barbeque beef; tens of thousands of people out west do it all the time. And it's oftentimes delicious. But it's "barbequed beef" not barbeque. The term barbeque is always properly reserved for pork. (emphasis mine)
Another great food map: The Sweet Tea Line, the availability of sweet tea in Virginia as a representation of the Mason-Dixon line. Did you know that South Carolina is the first place in the
United States where tea was grown and is the only state to ever have
produced tea commercially? More ice tea and sweet tea history.