Andrew carnegie and john d. rockefeller were both giant industrialists. compare and contrast the way they entered into, controlled, and dominated their respective industries?

Andrew Carnegie made his money through "vertical integration" -he became wealthy for his steel . Through vertical integration, he owned US STEEL and ALL the steps to make the final products (steel).
John D Rockefeller made his money through "horizontal integration" for his OIL. It was STANDARD OIL actually. 
They both monopolized their industries using brutal tactics though, in which they were similar. 

Andrew Carnegie and John D. Rockefeller were both very rich men and, if they were alive today, they would be the two richest men in the entire world. They both owned major companies that monopolized their respective industries and crushed all competition. They were both philanthropists. They both used railroads to keep their prices low.