People in the United States had long been displeased with the unsafe conditions, political corruption and social injustice of the industrial age, but it was not until the late 19th century that the proliferation of cheap newspapers and magazines galvanized widespread opposition. Writers directed their criticisms against the trusts (oil, beef and tobacco), prison conditions, exploitation of natural resources, the tax system, the insurance industry, pension practices and food processing, among others.
Theodore Roosevelt, however, became angry when he read a bitter indictment of the political corruption of the day. The president, clearly one of the most fervent reformers, believed that some of the writers were going too far, and cited the muckraker image in a speech criticizing the excesses of investigative journalism. The writers, many of whom had been Roosevelt's ardent supporters, harshly criticized him for apparently deserting their cause.
Historians agree that if it had not been for the revelations of the muckrakers the Progressive movement would not have received the popular support needed for effective reform.