Symbols are objects, characters, figures, and colors used to represent abstract ideas or concepts.
Perhaps the novel’s most important symbol is the animal pens and slaughterhouses of Packingtown, which represent in a simple, direct way the plight of the working class. Just as the animals at Packingtown are herded into pens, killed with impunity, made to suffer, and given no choice about their fate, so too are the thousands of poor immigrant workers forced to enter the machinery of capitalism, which grinds them down and kills them without giving them any choice. Waves of animals pass through Packingtown in a constant flow, as thousands of them are slaughtered every day and replaced by more, just as generations of immigrants are ruined by the merciless work and the oppression of capitalism and eventually replaced by new generations of immigrants.
Historically, The Jungle’s most important effect was probably the passage of the Pure Food and Drug Act of 1906, enacted in response to public outcry over the novel’s portrayal of the meat industry’s practice of selling rotten and diseased meat to unsuspecting customers. Sinclair uses the cans of rotten and unhealthy meat to represent the essential corruption of capitalism and the hypocrisy of the American Dream. The cans have shiny, attractive surfaces but contain a mass of putrid meat unfit for human consumption. In the same way, American capitalism presents an attractive face to immigrants, but the America that they find is rotten and corrupt.
The novel’s title symbolizes the competitive nature of capitalism; the world of Packingtown is like a Darwinian jungle, in which the strong prey on the weak and all living things are engaged in a brutal, amoral fight for survival. The title of the novel draws attention specifically to the doctrine of Social Darwinism, an idea used by some nineteenth-century thinkers to justify the abuses of wealthy capitalists. This idea essentially held that society was designed to reward the strongest, best people, while inferior people were kept down at a suitable level. By relating the story of a group of honest, hardworking immigrants who are destroyed by corruption and evil, Sinclair tries to rebut the idea of Social Darwinism, implying that those who succeed in the capitalist system are not the best of humankind but rather the worst and most corrupt of all.