1.) I need to smoke meat. (Not want... Need.)
2.) I have no concept of how to weld, and acetylene torches might as well be magic wands.
3.) I'm cheap.
(Well, as we'll later find out, maybe not so much on the last one...)
Meat smoking has been around for centuries, possibly as long as mankind has been alive. Originally used for fish, its primary function was believed to have been to keep flies away from the drying meat. Despite our primitive understanding of the fly reproduction cycle, we still figured out that flies make stuff rot... Rotting was bad... And flies didn't like smoke. This later lead to the preservation of many different kinds of meat through smoking.
Early smoking would have been as simple as hanging the meat near a fire, and then every time the wind changed, swearing out loud and going to move the drying rack. As time went on and we learned how to do much more advanced things (such as brewing beer) we would have advanced to the phase of swearing, then telling the kids to go move the drying rack. Eventually we learned how to build structures and the smokehouse was born, but swearing is still a long and time honored tradition with barbeque.
With the advent of the smokehouse, smoking of large amounts of meat could be done by a single family, enabling them to put away a surplus of food for harder times. Unfortunately, not everyone could afford to build a smokehouse, and as time went on, not everyone would even want to. Keeping a smokehouse going required a significant amount of wood and effort, and became obsolete as soon as grocery stores and refrigeration were available to the common man.
At some point, a man that will henceforth be referred to as "Jesus" realized that with a "smoker" we could have the flavor of smoked food combined with the convenience of a grill and the BBQ Smoker was born.
It may not have really happened that way, but that's how I like to remember it.
In all reality, the invention of "barbeque" is a mystery. Some attribute the word to the French term "barbe a queue" meaning "Beard to Tail", while others say it comes from the Caribbean Taino Indian word "barbacoa" - which basically means a meat-smoking apparatus such as a "smoker." In fact, the Taino barbacoa would eventually lead to Mexico's form of barbacoa that is a mouth-watering slow-cooked mess of beef or goat (typically from the head, or more specifically the "cheeks" of the animal) which should be another instructable all by itself. I suspect that the truth lies somewhere in the middle. With America being the melting pot that it is, the Taino "barbacoa" and the French "barbe a queue" were likely to have been merged to refer to the type of cooking that made every part of the animal delicious.
In America, the barbeque, like almost everything considered truly American, originated with the cowboys. On long cattle drives, they were often left with the "garbage" hunks of meat such as the brisket and ribs. These cuts would have either had little meat on them, or been incredibly lean resulting in very tough hunks when cooked traditionally. It's little surprise then that they're the very cuts of meat that have become the staple of today's barbeque. A cattle drive's "cookie" (the resident cook) would travel quickly ahead of the herd in his canvas chuck (food) wagon, and choose the evening's camp site far ahead of the cowboys. He'd immediately get started setting up shop, and begin slow cooking the cheap meats (and beans) to make them more palatable to the cowboys when they arrived for dinner. This is also where we get baked beans, corn bread, and most of the other things we associate with a good barbeque.
Today when you mention "barbeque" people will think about throwing a hotdog or a couple burgers on the grill. But if you invite me to a "barbeque" and there's not some sort of slow-smoked meat involved, I'll hope you step on a Lego.
So an important note about this build: If you want a "set it and forget it" smoker, this is NOT the smoker for you!
This grill does not have a thermostat or propane (I suppose someone a bit handier than me could add that, though). This is a raw charcoal and wood burner, which means everything from the outdoor temperature, to the wind, to whether or not the sun is behind a cloud will impact the temperature inside the smoke chamber. You will have to babysit this smoker (about every half hour) for the entire 10+ hours that you're smoking! Make sure you understand this before you try building the thing then telling me it doesn't work. This is the nature of this design (and I'd argue every design using wood and charcoal).