The John D Rockefeller bio is interesting: His father made a living selling quack medicine. John D left home and struck oil. He liked the idea of getting stuff for free out of the ground and selling it for a profit so he expanded into mining and quarrying. Then he saw what happened to those raw materials and realised he was missing some more profits so he expanded into chemicals. From chemicals he went to pharmaceuticals - even more money from even less raw material.

To help his new drugs industry he had textbooks rewritten and gave money to medical schools that would promote his drugs. He completed the circle and the Rockefellers were, once again, in the quack medicine business.