What is a common description of john d rockefeller and andrew carnegie​

But when he was 38 he started the Keystone Iron Works, and he stayed with that until 1901. By then Keystone Iron had become U.S. Steel, and Andrew Carnegie had become one of the wealthiest men on the planet. John D. Rockefeller went into business when he was 20, and he picked up his first oil well as a sideline.

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powers  are  denied  to the  national governmentin three distinct ways: some  powers, such as the  power  to levy duties on exports or prohibit the freedom of religion, speech, press, or assembly, are expressly  denied  to the  national government  in the  constitution.