Muckrakers were investigative journalists in the early 20th century who aimed to expose corruption, social injustices, and unethical practices in politics and business. They played a crucial role in the Progressive Era by bringing attention to issues such as child labor, corporate greed, and political corruption. Their work often led to public outcry and reforms. Prominent muckrakers included Upton Sinclair, whose novel The Jungle revealed unsanitary conditions in the meatpacking industry, and Ida B. Wells, who fought against lynching and racial discrimination. Their writings helped inform the public and prompted legislative changes to improve society.