The Jungle exposed the horrible conditions of the U.S. meatpacking industry and a corrupt economic system. Its vivid and horrifying depiction of the slaughterhouse, the dangers of contamination and injury - conditions which were rife before any real regulation was set in place. The Jungle was in fact the catalyst for the 1906 Pure Food and Drug Act.

The Rudkus family has moved to Chicago's Packingtown district looking for the good life, but run into trouble at every step with fraudulent, usurious tactics. Here we find some of the famous descriptions of the gruesome slaughterhouse, filled with danger and disease. In the second part, Jurgis eventually loses his job and family and is out on the street, and gets swept up by a meeting of Socialists. From here the book turns into a didactic lecture about how socialism will cure all ills. With the money from this bestseller Sinclair founded a socialist colony in New Jersey, which "mysteriously" burned to the ground within a year.