From whole hogs to smoked fish and brisket, this all-American smoke-infused cooking style is as diverse as the US itself – and just as rich in history. In the US, "barbecue" is both noun and verb – a familiar siren, calling from a squat cinder block building with its smoky aroma of meat and char. Depending where it's prepared, it could be a multi-napkin pulled pork sandwich, a tray of hand-sliced brisket or smoked chicken wings tangy with mayonnaise, accompanied by a litany of rib-sticking sides. The country's wildly diverse barbecue canon evolved from a single style born during the...