Final answer:
Andrew Carnegie used the Bessemer process to produce steel for railroads, dominating the U.S. steel market through his Pittsburgh-based Carnegie Steel Factory.
Step-by-step explanation:
Andrew Carnegie and the Bessemer Steel Process
Andrew Carnegie used the Bessemer process for the mass production of steel, which was essential for building railroads. This process involved blowing cold air over hot iron to remove impurities, resulting in stronger and cheaper steel. Utilizing this technological advancement, Carnegie founded the Carnegie Steel Factory in Pittsburgh, allowing him to dominate the U.S. steel market and produce more steel than all of Great Britain by 1900. His business strategies included vertical integration, which involved owning all steps of the production process, from the raw materials right through to transportation, enabling reduced costs and improved product quality.