Before the assembly line, there was the disassembly line. Midwestern pork processing plants in the mid-nineteenth century launched America down the road to industrial meat production with their eye-poppingly efficient system for converting pigs into cuts of meat. Once the time-consuming labor of specialized butchers, the disassembly lines of Cincinnati and Chicago cranked out thousands of hogs in a single day. When William “Pa” Klann, head of the engine department at the three-year-old Ford Motor Company, visited Chicago in 1906 he had a flash of inspiration: this mechanized process of dismemberment could also be applied in reverse.

Ever since Columbus brought eight hogs to Cuba in 1493, pigs and Europeans have cooperated in overrunning the North American continent. Omnivorous, voracious, and without any natural predators, pig populations mushroomed in the New World. These grunting meat machines were low-maintenance and avid foragers, making them ideal livestock for colonists contending with an alien environment. They also grew fast and bred fast: Hernando de Soto arrived in Florida in 1539 with thirteen pigs; when he died three years later, their number had swollen to 700.

These self-sufficient meals on legs accompanied America’s westward expansion, and pig farming flourished in the Midwest. Cold enough to preserve the meat in winter, and with supply routes to both the South and the east coast, Cincinnati became the first major hub of pork production. Drovers from across the Midwest herded swine in their thousands up to “Porkopolis,” and Cincinnati’s streets were notoriously jammed with pedestrian-jostling hogs. At the outbreak of the Civil War, Cincinnati was America’s seventh largest city, numbering 160,000 human beings and processing over 400,000 pigs each year.

More remarkable than the throng of swine passing into Cincinnati was the manner in which they came to be shipped out again. In a competitive market squeezed with over 70 firms by the end of the Civil War, efficiency was everything. The hog merchants of Porkopolis vied to hustle the most pork through their plants each day for the least cost.

The heat of competition forged the disassembly line. The once separate enterprises of slaughtering, butchering, and meatpacking were consolidated into a single, ruthlessly systematic process. Held in pens on the upper floor of the packing plants, pigs had their heads smashed by sledgehammers and their legs tied with a rope that lowered them down to the cutting floor. There, teams of four would chop an entire carcass into the desired cuts in under a minute, each member turning or chopping the carcass in a repetitive procedure. The butchers threw each cut down its own designated slide to be smoked, salted, or iced, and packed into barrels. The incessant flow of gore issuing from the plants gave nearby Deer Creek the nickname “Bloody Run.”

Cincinnati’s pork industry extended far beyond meatpacking, with hog merchants peddling “everything but the squeal.” Inedible bits of fat, grease, bone, and bristle found their way into candles, soap, glue, gelatin, and fertilizer. Rendered pig products were the cornerstone of the corporate empire founded by candlemaker William Procter and soapmaker James Gamble in Cincinnati in 1837.

Procter & Gamble became a nationwide brand on the strength of contracts earned supplying Union troops, but the Civil War also spelled the decline of Cincinnati as the nation’s chief pork processor. Much of Cincinnati’s pork travelled down the Ohio and Mississippi Rivers toward New Orleans, supplying Southern markets whose cotton farming limited local pork production. With the outbreak of hostilities, that supply stream dried up. Chicago was quick to capitalize on Cincinnati’s misfortune, taking advantage of its superior rail connections to farms in Iowa and Illinois and to cities in the northeast. The Union Stock Yards opened on Christmas Day, 1865, consolidating Chicago’s meatpacking industry and making the city “Hog butcher for the world,” in Carl Sandburg’s phrase.

In the Yards of Chicago, the disassembly line soared to new heights of efficiency. Pioneered by meat magnates like the imperious Philip Armour, Chicago’s meatpacking plants used steam-powered hoists to yank hogs tied by the legs onto an overhead trolley rotated by a horizontal wheel. Standing on the cutting floor below, a predominantly immigrant labor pool converted live pigs into meat products in a thirteen-step process of hanging, throat-cutting, scalding, cabling, scraping, cleaning, washing, inspecting, de-gutting, de-larding, decapitating, splitting, and chilling. By the end of the 19th century, more than 12 million animals passed through the Yards every year.

In 1906, Pa Klann visited a plant founded by Gustavus Swift, who had also pioneered the use of refrigerated railway cars for shipping meat out east. Klann had joined Ford the previous year, having previously worked as a machinist repairing grain elevators and other mechanical conveyers in the breweries of Detroit. Already familiar with the benefits of mechanical conveyance on a small scale, Klann immediately saw the far-reaching potential of the disassembly line: “If they can kill pigs and cows that way, we can build cars that way.”

In essence, the genius of the assembly line was the idea of moving material rather than workers. Starting with an overhead hopper that zipped sand around the foundry, Ford’s production chiefs experimented with increasing boldness with this new paradigm. Klann and others tinkered with different parts of the process, gradually streamlining production with rails and then conveyer belts.

These developments culminated in the revolutionary assembly line that opened at Highland Park on October 7th, 1913. A motor and rope pulled a continuously moving conveyer belt, which carried the chassis of the Model T through its various stations of assembly. On October 6th, it took more than twelve man-hours to assemble a Model T. Within twenty-four hours, it was down to six. Within a year of further tweaking, Ford’s assembly lines were spitting out a new car every ninety-three minutes. The main hold-up in the assembly process was the paint, which didn’t have time to dry. Because japan black was the fastest drying paint on the market, Ford offered his Model T in “any color as long as it’s black.”

Rapid and heavily mechanized production lines kick-started two of America’s great love affairs: inexpensive meat and motor cars. Today, over one billion animals are killed each year and make their shrink-wrapped way to refrigerated supermarket shelves, and Americans own 808 cars for every 1000 people—more than any other country besides Grand Prix-loving (and wealthy) Monaco. The workers who produce them don’t have to move a step.