The railroads were fighting fiercely for traffic and, in an attempt to create a cartel to control freight rates, formed the South Improvement Company in collusion with Standard and other oil men outside the main oil centers. The cartel received preferential treatment as a high-volume shipper, which included not just steep rebates of up to 50% for their product, but also rebates for the shipment of competing products. Part of this scheme was the announcement of sharply increased freight charges. This touched off a firestorm of protest from independent oil well owners, including boycotts and vandalism, which eventually led to the discovery of Standard Oil's part in the deal....
Undeterred, though vilified for the first time by the press, Rockefeller continued with his self-reinforcing cycle of buying competing refiners, improving the efficiency of his operations, pressing for discounts on oil shipments, undercutting his competition, making secret deals, raising investment pools, and buying rivals out. In less than four months in 1872, in what was later known as "The Cleveland Conquest" or "The Cleveland Massacre," Standard Oil had absorbed 22 of its 26 Cleveland competitors....If they refused his offer, he told them he would run them into bankruptcy and then cheaply buy up their assets at auction....
By the end of the 1870s, Standard was refining over 90% of the oil in the U.S. Rockefeller had already become a millionaire....
The firm was attacked by journalists and politicians throughout its existence, in part for these monopolistic methods, giving momentum to the antitrust movement. By 1880, according to the New York World, Standard Oil was "the most cruel, impudent, pitiless, and grasping monopoly that ever fastened upon a country."....
One of the most effective attacks on Rockefeller and his firm was the 1904 publication of The History of the Standard Oil Company, by Ida Tarbell, a leading muckraker. She documented the company’s espionage, price wars, heavy-handed marketing tactics, and courtroom evasions Although her work prompted a huge backlash against the company, Tarbell claims to have been surprised at its magnitude. “I never had an animus against their size and wealth, never objected to their corporate form. I was willing that they should combine and grow as big and wealthy as they could, but only by legitimate means. But they had never played fair, and that ruined their greatness for me.”