What practices had rockefeller used to establish used to establish standard oil company?

In 1870, he established standard oil, which by the early 1880s controlled some 90 percent of u.s. refineries and pipelines. critics accused rockefeller of engaging in unethical practices, such as predatory pricing and colluding with railroads to eliminate his competitors, in order to gain a monopoly in the industry.
tarbell exposed unfair practices of the standard oil company, leading to a u.s. supreme court decision to break its monopoly.