Final answer:
Using horizontal integration, Standard Oil, led by Rockefeller, would acquire other companies, thus reducing competition and gaining market dominance. Prices of their products would initially decrease due to efficiencies and then would be raised significantly once competition was eliminated and control was established.
Step-by-step explanation:
Before 1900, business owners like John D. Rockefeller used horizontal integration to gain control over other companies in the same industry. By merging with or driving out competitors, his company, Standard Oil, managed to significantly reduce competition. As Standard Oil took control of the market, they would typically raise oil prices substantially, taking advantage of their monopoly to maximize profits.
Rockefeller’s approach to business and trusts enabled Standard Oil to dominate the oil industry. Standard Oil's control over 90 percent of the nation's refineries by the 1890s meant they could set higher prices without the concern of being undercut by competitors.
Despite the initial lowering of kerosene prices due to increased efficiency in the industry, the ultimate result of this monopolistic control meant that, once competitors were out of the way, prices were raised to much higher rates, maximizing profits for the monopolized entity at the expense of consumers and remaining competitors.