Which businessman created a monopoly in the oil industry?

John D. Rockefeller is known for creating a monopoly in the oil industry through his company, the Standard Oil Company, founded in 1870. Rockefeller implemented aggressive business practices that included both horizontal and vertical integration. By acquiring many competitors and controlling various stages of production and distribution, he was able to dominate the market. His practices led Standard Oil to control a significant percentage of the U.S. oil refining industry, giving him unprecedented influence and financial power.

In contrast, Andrew Carnegie was prominent in the steel industry, Henry Ford is recognized for revolutionizing the automobile manufacturing process with the assembly line, and J.P. Morgan was a major figure in banking and finance, known for consolidating industries but not specifically for creating a monopoly in oil. Thus, the focus on Rockefeller clearly distinguishes him as the key figure in establishing a monopoly within the oil sector.