Cooking and smoking meat over fire have been around since before the start of recorded history. In fact many anthropologists will tell you that when our human ancestors started cooking their food profound changes occurred in our species and made us the primates we are today. Because we don't know which upright walking hominid was the first one to put meat over fire I'm going to try to explain the history of the term "barbecue" and its transformation over time.
The New World
The first term sounding anything like barbecue was written down in the early 1500s by a Spanish explorer. He was referring to the local populations method of cooking strips of meat by hanging them on wooden racks over smoking fires. The Taino Indians had been cooking this way in order to preserve meat in the hot climate on the Caribbean. The word was also used by other Spaniards to describe wooden sleeping racks, so its not known what the term meant in the Taino language.
Pirates!
Pirates invented barbecue? Well, not really, but they did have a pretty strong connection. The synonym that many people use for pirate "buccaneer" is actually based on the fact that they smoked all of the meats that they carried on their ships. In French "Boucan" was the term used to describe the wild men who hunted on the sparsely inhabited Caribbean islands in the 1500-1600s. As these men began acquiring ships and turning to piracy the word evolved into buccaneer.
Barbecue in America
In the American south the pig was the primary source on meat before the civil war. They were semi wild and lived off the land. This made for a much tougher and stringier type of meat. Cooking entire pigs in open pits was a community event. Because the meat was so tough the low and slow cooking technique we know today was developed.
Over time church picnics began to resemble the barbecue parties we know today with multiple cooks preparing their own dishes for everyone to enjoy.
Modern Barbecue
The modern barbecue era began in the 1950s and it came about because of the automobile. Small restaurants began popping up on roadsides all around the south to feed travelers, and most of them served barbecue. This is likely where the initials BBQ come from (it was shorter than writing out the entire word). Different regions began developing their own styles of barbecue, and exchanging ideas as they traveled.
Tennessee
Tennessee barbecue is based around pulled pork, which has been slow cooked and then shredded by hand instead of being chopped up. Then it is saturated with a sweet tomato based sauce. The same sauce is also used on slabs of ribs
North Carolina
In North Carolina the primary type of barbecue is sliced or chopped pork with a peppery vinegar based sauce.
Alabama
In Alabama pulled and chopped pork are found, served with a spicy red sauce. Ribs are also found
South Carolina and Georgia
Chopped pork with a mustard based sauce is the most common. Deep fried pig skin "pork rinds" are also often seen.
Texas
Texas barbecue is all about the beef. Setting it apart from the traditional pork barbecue that much of the south enjoys.