Answer:
The factor that contributed to the spread of Progressive ideas during the late 19th century and early 20th century is the increasing public awareness of political corruption and business abuses
Step-by-step explanation:
American society was not totally aware of many factors related to politics and economics before all the social movements such as the Industrial Revolution and the consequent Progressivism, these factors made them notice irregularities that were not going to be accepted anymore, then a change was demanded by people at the beginning of a new Era.