Journalists who exposed the wrongs of American society during the Progressive era were known as:

A) Abolitionists
B) Know-nothings
C) Stand-patters
D) Muckrakers

Muckrakers

Journalists and writers of the late 19th and early 20th centuries who sought to expose social ills and corporate and political corruption, aiming to spur public reform.

American Society

The societal structure and cultural norms of the United States, characterized by its diverse population and values such as freedom and democracy.