Plate taken from 'Scientific American' (Vol LXV, November 1891) illustrating the succesive operations from the catching pen where the hog, is killed to cooling the meat after procesing. As an important rail hub connecting the east and the expanding west of the United States, Chicago became the centre of the American meat packing industry in the mid 19th century. Originally the procesing of meat was carried out in a number of small stockyards, but as the industry grew rapidly, nine railway companies combined to purchase a 320 acre piece of land in 1864, on which the Union Stock Yards were built. By 1900 the stockyard covered 475 acres, and Chicago's meat procesing industry employed 25,000 people and produced 82% of the meat consumed in the United States.
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