How did John D Rockefeller impact big business?

John D. Rockefeller revolutionized big business through the creation of the Standard Oil Company, which set the standard for corporate structure and strategy in the late 19th and early 20th centuries. He pioneered practices such as horizontal integration, acquiring competing oil companies to eliminate competition and monopolize the market. His business tactics, including aggressive pricing strategies and efficient production methods, significantly lowered costs and increased consumer access to oil products. Rockefeller's influence also led to the establishment of regulatory measures aimed at curbing monopolistic practices, shaping the landscape of American business.