Answer:
The sinister business practices of Standard Oil.
Explanation:
She was an American writer and investigative journalist in the late 19th and early 20th century. She is well known for her 1904 book "The History of the Standard Oil Company". In the book, she investigates the company owned by Rockefeller and was an example for many other journalists to write about the attempts to gain monopolies in various industries.
Her work contributed to the dissolution of the Standard Oil monopoly in 1911 after the Supreme Court of the United States found the company guilty of having violated the Sherman antitrust act.
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