Cooks have introduced new flavors into old recipes since the beginning of time, as far as we know. In the past, however, this was a natural process--something people did without much acknowlegement. The "fusion" trend that dominated the '90s and '00s is different in that it celebrated globalization.
8. Diana Kennedy
It wasn't her doing, really. But the publication of her The Cuisines of Mexico in 1972 recognized Tex-Mex as a unique, regional cuisine. Shortly thereafter (with help from Jimmy Buffet and Howard Cosell) margaritas, nachos and other Texas staples were everywhere.
7. The "Greatest Generation"
This was, of course, the generation that accepted racial inequality and the blacklisting of so-called communists, but so be it. In dining terms, they provide modern benchmarks. Depression era shortages, wartime rationing and the increasing number of mothers in the workforce caused them to relish convenience foods. Their increased mobility set the groundwork for fast food chains. Familiarity with technology in factories or on the battle fronts spurred demand for kitchen gadgets.
6. Julia Child
There were other early TV chefs--the Galloping Gourmet comes to mind--yet she was the first celebrity. She wrought not just the vapid Food Network stars of today, but the first nudge toward appreciation of global techniques seemingly lost over a few decades of economic calamity, war and postwar "we're number one" enthusiasm.