How did John Davidson Rockefeller get rich?            
            
            
                                            
                
                
                    by selling supplies to the army
                    
                    
                 
                
                    by mining diamonds and gold
                    
                    
                 
                                            
               
                                                                                   
            John Davison Rockefeller was the founder of the Standard Oil Company, which dominated the oil industry in the U.S. As kerosene and gasoline grew in importance, Rockefeller's wealth soared, and he became the world's richest man and first American worth more than a billion dollars.