Upton Sinclair's landmark 1905 book, "The Jungle," exposed the food contamination and worker exploitation hidden in the fetid stockyards and meatpacking plants of Chicago and other major American cities. The muckraking journalist dubbed the nasty and brutish meat factories "a monster ... the Great Butcher ... the spirit of capitalism made flesh."

The nauseating details of worker and consumer abuses that Sinclair exposed were so horrific that the ensuing public revulsion and outrage were transformative. Congress quickly passed a food purity law (the 1906 Federal Meat Inspection Act), and union organizing drives sparked nationwide contract bargaining that eventually gave long-oppressed meatpacking workers the clout to improve factory conditions and pay. Indeed, by 1970, the Amalgamated Meat Cutters and the United Packinghouse Union had won enforceable safety rules and solid middle-class wages — about $25 an hour in today's dollars. Now the median wage for hourly workers in meatpacking plants is down to about half that — $13.23 per hour — some 30 percent less than production workers in other manufacturing jobs.