How did horizontal integration enable Rockefeller to monopolize the us oil industry?

Horizontal integration allowed John D. Rockefeller to consolidate control over the oil industry by acquiring competing oil refineries and companies. By purchasing rivals, he reduced competition and created a vast network of oil production and distribution under the Standard Oil Company. This strategy not only increased his market share, but also enabled him to negotiate favorable rates with railroads for transportation, further solidifying his dominance in the industry. As a result, Rockefeller effectively monopolized the U.S. oil market, controlling prices and supply.