The story starts with European colonisation of North America and the settling of the Great Plains during the nineteenth century. The settlers, in effect, engaged in genocide against the Native Americans while at the same time eliminating most of the wild animals on the Great Plains. In fact, it was understood that every dead bison meant a dead Native American. And so genocide was accompanied by speciecide. Wikipedia estimates that at the beginning of the nineteenth century between 25-35 million bison roamed the plains. By the 1880s, only a few hundred bison remained and, like the Native Americans, had been restricted to living in reserves.
Initially the massive herds of bison that once roamed freely were replaced by cattle farming on the open range. These cattle were driven to railroads to be transported in cattle-cars to cities to be slaughtered in industrial slaughterhouses like the Chicago stockyards. The mass killing of bison was replaced by the mass killing of cattle on a scale never seen before. The cattle ranging was accompanied by ecocide - the destruction of ecosystems and biodiversity - which was hastened by the fenced farms that eventually replaced the open range. Agriculture involves the domestication of the wilderness and the farming of favoured, commercially valuable domesticated plants and animals on land once occupied by wild fauna and flora.
The industrialist Henry Ford was hugely impressed with the efficiency with which the Chicago disassembly lines took apart the bodies of slaughtered animals. It has been argued that this is where Ford got the idea of the assembly line, which transformed modern industry. Without technologies similar to those used in industrial processing, the Nazis would not have managed to murder and process the bodies of so many Jews during the Holocaust. In many cases Jews were even transported to the death camps in cattle-cars.
In his preface to the 2004 edition of his book The Case for Animal Rights, Tom Regan estimated that 48 000 000 000 (that is, 48 billion) land animals are slaughtered annually for food, more than 5 million every hour. This does not include the countless marine animals "harvested" from the oceans. Thirteen years later, the numbers must be even more horrifying. Humans have turned this planet into a massive and gory death machine processing innumerable animal bodies to feed their apparently insatiable blood lust. At the same time agriculture, particularly the meat and dairy industry, is one of the main driving forces behind climate change and ecological destruction on the planet.