Which robber baron became one of the wealthiest people in the world by creating a trust that controlled most of the oil refineries in the United States? A. John D. Rockefeller B. Cornelius Vanderbilt C. Andrew Carnegie D. John Jacob Astor
Rockefeller worked with oil, Vanderbilt did the railroads, Carnegie was leader of the American steel industry, and Astor did fur trade and invested in real estate.
