The idea seemed simple enough: Build a case to confer landmark status to the location where Chicago-style deep-dish pizza was invented.

But as historian Tim Samuelson began to look into origins of the distinctive dish, he found himself mired in conflicting stories, each as impenetrable as the pizza and peopled with characters every bit as robust. There is almost no documentation about who invented the dish, and without it, legend has taken over.

The only paper trail indicates the pizza almost certainly came out of a 19th Century mansion built with lumber money at 29 E. Ohio St.—the restaurant now known as Pizzeria Uno. But the question of who exactly developed the concept remains a mystery despite the best efforts of the City of Chicago's official cultural historian.