The University of North Texas's Portal to Texas History has put the WPA's 1942 book Houston: A History and Guide online.
It turns out that the somewhat enigmatically named chapter "Strangers at the Gates" deals with the history of Houston's hospitality industry. Houston, it seems, not only was on the leading edge of still-extant trends in fast-food methods, but also home to one unique, likely never-replicated innovation:
At great numbers of 'drive-ins,' where sandwiches, other foods, beer, and soft drinks are sold, automobilists are served by comely girls, many of them revealingly attired. They and their costumes - often of silk or satin, some including capes, others white boots and plumed hats - have been portrayed in national magazines and newsreels as a colorful Houston characteristic. At some of the larger of these establishments between 50 and a hundred of these 'car-hops' are employed.Somehow, we think it would be easier to staff a place like that today than it was in 1942. (By the way, does anyone remember that place?)
Although most drive-ins demand that these waitresses be young and trim-figured, one employs only 200-pounders, who wear tiny skirts in summer and slacks in winter.