Fajita Update

Joel and Kevin undertake to educate me on the concept of fajita.  Turns out that "fajitas," though descending from traditional habits and patterns, are not themselves really a traditional dish and are "Mexican" only if you ignore the treaty of Guadalupe Hidalgo--which is to say, more Tex than Mex, and in a sense created for its American audience.  Kevin routes me to the Wiki:

The first serious study of the history of fajitas was done in 1984 by Homero Recio as part of his graduate work in animal science at Texas A&M. Recio was intrigued by a spike in the retail price of skirt steak, and that sparked his research into the dish that took the once humble skirt steak from throwaway cut to menu star. Recio found anecdotal evidence describing the cut of meat, the cooking style (directly on a campfire or on a grill), and the Spanish nickname going back as far as the 1930s in the ranch lands of South and West Texas. During cattle roundups, beef were butchered regularly to feed the hands. Throwaway items such as the hide, the head, the entrails, and meat trimmings such as skirt were given to the Mexican vaqueros (cowboys) as part of their pay. Hearty border dishes like barbacoa de cabeza (head barbecue), menudo (tripe stew), and fajitas/arracheras (grilled skirt steak) have their roots in this practice. Considering the limited number of skirts per carcass and the fact the meat wasn't available commercially, the fajita tradition remained regional and relatively obscure for many years, probably only familiar to vaqueros, butchers, and their families.

Sonny Falcon is believed to have operated the first commercial fajita taco stand at a weeklong outdoor event in Kyle, Texas, in 1969.  ... The food became popular in ... Mexican and Tex-Mex restaurants in Houston and San Antonio, Texas. ...In southern Arizona, the term was unknown except as a cut of meat until the 1990s, when Mexican fast food restaurants started using the word in their marketing. For a good period of time, McDonalds served chicken fajitas on their menu. In many restaurants, the fajita meat is brought to the table sizzling loudly on a metal platter or skillet, with the tortillas and condiments served on the side.

Link.  "Fajitas," then seem to me to fall into a class of lately-evolved cultural achievements, somewhat akin to Chicago deep dish pizza or bluegrass music or, going further back, the blues or chop suey.