USA; Chicago - The Yards (Great Union Stock Yards of Chicago (also: Union Stock Yard & Transit Company); large companies of the American meat industry in the New City district. Around the world's largest slaughterhouse (1865-1971); the American meat processing industry (Armor and Company; Swift & Company etc.) The slaughterhouse itself was founded and operated by 9 railway companies and established Chicago's reputation as "hog butcher of the world".The slaughterhouse developed the industrialized production of meat (assembly line production) and was considered a model for Slaughterhouses worldwide.Packing of bacon in glasses at the Armor & Company meat factory.Stereo photography; 1909.