What factors prompted the Progressive movement?

There were
three main factors that caused the rise of Progressivism. 

First, there was
the economic boom and growth of industrialization that came about at the end of the 19th century
and the beginning of the 20th century.  This boom created huge companies and an economy in which
many workers worked in large factories.  It also brought about intense competition between
businesses and the need for them to be as efficient as possible.  These factors meant that
workers were getting to be mistreated and...