What scandalous practice did Upton Sinclair expose in his novel The Jungle?

Upton Sinclair's novel *The Jungle* exposed the horrifying and unsanitary conditions of the meatpacking industry in Chicago at the beginning of the 20th century.

While Sinclair's primary intention was to expose the exploitation of workers in the industry, the novel's vivid descriptions of rotting meat, diseased carcasses, and adulterated food products shocked the public and sparked a national outcry. These revelations led to the passage of the Meat Inspection Act of 1906 and the Pure Food and Drug Act of 1906, which established federal oversight of food safety and hygiene.