How did Rockefeller create monolopy?

John D. Rockefeller created a monopoly in the oil industry through aggressive business practices, including vertical integration and predatory pricing. By controlling every aspect of production and distribution, from oil extraction to refining and transportation, he minimized costs and maximized efficiency. Additionally, he often undercut competitors' prices to drive them out of business, ultimately consolidating control over the market. His company, Standard Oil, became synonymous with monopoly power in the late 19th century.