Pulled pork sandwich from Dickey's Barbecue Pit.

By most accounts, Americans love barbecue, and restaurants are aiming to fulfill that desire.

Sixty-three percent of chains tracked by research firm Technomic’s MenuMonitor used the word “barbecue” on their menus. But what exactly is barbecue?

A Kansas City man’s luscious plate of sauce-smothered beef served on a slice of white bread might strike a South Carolinian as a sickeningly sweet plate of barbarism. On the other hand, the mustard-and-vinegar-based smoked pork butt from South Carolina would be an affront to a Texan who, when invited to a barbecue, would expect slow-smoked beef brisket.

The often-quoted Australian exhortation to “throw a shrimp on the barbie,” would outrage American barbecue scholars — oh yes, they exist — who, despite regional differences, would insist that for something to be called barbecue it must be slowly cooked by the heat of smoke, not by the radiant heat of coals under a grill.

But others are fine calling anything with a somewhat sweet sauce on it “barbecue,” and millions of Americans will throw “barbecues” of their own over this long Independence Day weekend. Most of them, according to a recent Zagat survey of home barbecue habits, will grill hamburgers or steak. Chances are they will be cooked by flame rather than smoke, and not necessarily smothered in sauce of any kind.

The highly regional and idiosyncratic nature of barbecue might be why it remains a challenge for barbecue chains to succeed nationally, although Famous Dave’s may eventually show everyone else how it’s done. Or maybe Dickey’s Barbecue Pit, with its recent rapid expansion, has cracked the code.  

Take a look at some of the nation’s leading barbecue chains and what makes them tick: