Meat packing ranked as Chicago’s largest industry following the Civil War, producing a quarter of the city’s manufacturing output by 1868. Five large firms produced half of Chicago’s pork, then the city’s leading product. The packers dumped blood, offal, and manure into the Chicago River, despite an ordinance prohibiting them from doing so. They protested that to do otherwise would increase their costs, put them at a disadvantage against competitors elsewhere, and force them out of Chicago.
