Final answer:
Muckrakers focused on exposing injustices related to child labor, business corruption, and health and safety to drive reform during the Progressive Era. Their journalistic work led to significant changes, such as the Pure Food and Drug Act.
Step-by-step explanation:
Many muckrakers focused on exposing various injustices and social ills during the early 20th century. Their work was a catalyst for the Progressive Era, highlighting issues such as child labor, antitrust activities, the breakup of big businesses, and health and safety concerns. They aimed to agitate and elevate public consciousness to press for legislative change, confronting the abuse of power and neglected responsibilities in both government and big businesses. Their journalism led to significant reforms, including laws like the Pure Food and Drug Act. By revealing the disturbing conditions in industries such as meatpacking, exemplified by Upton Sinclair's 'The Jungle', muckrakers played a vital role in spurring public demand for better working conditions, more honest business practices, and consumer protection.