Book excerpt: On the South Side to tour the Union Stock Yard, people got a firsthand look at Chicago's industrial prowess as they witnessed cattle, hogs, and sheep disassembled with breathtaking efficiency. At their height, the kill floors employed 50,000 workers and processed six hundred animals an hour, an astonishing spectacle of industrialized death. Pacyga chronicles the rise and fall of an industrial district that, for better or worse, served as the public face of Chicago for decades. He takes readers through the packinghouses as only an insider can, covering the rough and toxic life inside the plants and their lasting effects on the world outside. He shows how the yards shaped the surrounding neighborhoods; looks at the Yard's sometimes volatile role in the city's race and labor relations; and traces its decades of mechanized innovations.