Political Machines Across the U.S.
The inspiration for his book came from an article he edited for "McClure's" by an author who had written of a public official who had been elected strictly on the strength of an alliance between local businesses and a leader in the local Democratic party. The previous author had omitted crucial details that proved to be the real strength of the article and Steffens felt passionate enough about the issue to rewrite the entire article over again, including all of the juicy details and being as harsh as possible to the corrupt officials, regardless of the slander charges or threats that would come because of it. He defied his boss, S.S. McClure, by doing so. He did the same in Minneapolis by exposing a system of organized crime that was able to thrive because the criminals payed off the mayor and policemen. Steffens found similar forms of corruption across the country in Chicago, Philadelphia and Pittsburgh.
This work, along with other muckraker's works, changed the political climate of the United States forever as it inspired the general public to fight back against big business' influence in government.