Final answer:
Upton Sinclair and other muckrakers exposed widespread corruption and problems in American society, leading to significant reforms such as the Meat Inspection Act and the Pure Food and Drug Act, which aimed to improve food safety and labeling.
Step-by-step explanation:
Muckrakers such as Upton Sinclair played a pivotal role in the Progressive Era by exposing societal problems and influencing governmental reforms. Sinclair's novel, The Jungle, provided a disturbing glimpse into the unsanitary conditions of the meatpacking industry.
This exposure not only caused a public outcry but also led to President Roosevelt's initiative to pass the Meat Inspection Act and the Pure Food and Drug Act in 1906, aiming to ensure the safety and cleanliness of meat products and to establish truthful labeling of food and drugs.
The muckrakers' efforts were instrumental in shining a light on corruption and abuses in various industries, which in turn mobilized public support for reform and the creation of regulatory agencies like the U.S. Food and Drug Administration (FDA).