Which journalist exposed the monopolistic practices of John D. Rockefeller and the Standard Oil Company?

Ida Minerva Tarbell (November 5, 1857 – January 6, 1944) was an American teacher, author and journalist. She was one of the leading "muckrakers" of the progressive era of the late 19th and early 20th centuries and is thought to have pioneered investigative journalism. She is best known for her 1904 book, "The History of the Standard Oil Company", which was listed as No. 5 in a 1999 list by New York University of the top 100 works of 20th-century American journalism. It was first serialized in McClure's Magazine from 1902 to 1904. She depicted John D. Rockefeller as crabbed, miserly, money-grabbing, and viciously effective at monopolizing the oil trade.

Her stories on Standard Oil began in the November 1902 issue of McClure's and lasted for nineteen issues. She was meticulous in detailing Rockefeller's early interest in oil and how the industry began. After the series was over, she wrote a profile of Rockefeller, perhaps the first CEO profile ever, though she never met or even talked to him. Tarbell developed investigative reporting techniques, digging into public documents across the country. Separately, these documents provided individual instances of Standard Oil's strong-arm tactics against rivals, railroad companies and others that got in its way. Organized by Tarbell into a cogent history, they became a damning portrayal of big business.