Which group of people worked to inform the public about injustices of the progressive era?

Muckrackers

Explanation:

The group of people who worked to inform the public about injustices of the Progressive Era were called "muckrackers." Muckrackers were journalists who reported on the problems of the time. These were often social problems. However, they also entered politics as they criticized leaders as corrupt or inefficient. Their purpose was to raise awareness of these problems in order to motivate society to change.

the answer is richard nixion