Need a midnight snack in California? Chances are, you're going to In-N-Out, the Golden State's favorite burger joint. Got the munchies in Texas? Whataburger's probably what you're after. Atlanta? Chick-fil-A, if it's not too late, otherwise Waffle House. (Obviously.) Midwesterners might crave cheese curds at Culver's, Chicagoans an Italian beef sandwich and one of those chocolate cake shakes from Portillo's, while New Yorkers might fire up the Postmates app and order from Shake Shack.

Lucky enough to live in Phoenix? These days, you can choose from any of the above, and then some. Chicken fingers from Raising Cane's. Free peanuts at Five Guys. Detroit-style pizza at Jet's. Those thin, crispy burgers from Steak 'n Shake. Breakfast sandwiches at Dunkin' Donuts. Tacos, Texas-style, at Fuzzy's. Italian subs piled high with hot peppers at Potbelly. Avocado-topped burgers from that other California chain, Habit. You name it, and Phoenix is eating it, every night of the week—sometimes all pretty much on the same street corner.

Watching so many worlds collide like this can be a little jarring to unlucky visitors from more deprived regions, but Phoenix isn't actually all that unique—this flooding of the fast-food zone is a story that's being repeated over and over again, all across the quickly-growing Sunbelt, a part of the United States that has been taking on large numbers of new arrivals from all over the country for generations now. With, say, so many Midwesterners having decamped for warmer climes, it makes sense that a prized regional brand like Culver's from back home would eventually start franchising in these new markets. Sometimes, however, the moves are even bolder, with staunchly regional companies identifying a major growth opportunity and then taking a major leap.