Matt is almost correct, except that the idea of this meat wrapped in a tortilla, with whatever type of "fixins" and spices came from a lot further back than a fast food chain. Actually this is a Tex-Mex invention by South West cowboy cooks in the mid 1800s who got the idea of wrapping grilled sliced beef in a flour tortilla, rolling it up and giving it to the guys who were still out riding herd. I have an old Los Angeles cookbook which gives a recipe for that very item...a very long time before fast food joints! This book is dated 1905! Got a lot of other interesting stuff as well, for after all, the Spanish were in California long before the Anglos. However, Matt is also correct in saying that all that other stuff added to the fajita was not the normal mode. That something similar would also be in Mexico, but with a soft corn tortilla, is not surprising. The flour tortilla came long after original corn tortilla, as corn was the only grain available. Wheat came along a lot later. Don(Rael)could jump in here, as he has a great knowledge of food history, I believe. So, a little bit of ancient history from the ancient chile head :-D !! Cheers, Doug in BC