Written by somebody else:
“Carnegie transformed steel from a scarce semi-precious metal of variable poor quality to a cheap and plentiful commodity of high quality and selectable and predictable properties. This metal became the very bones of civilization.

He did so in the span of one productive lifetime.

Rockefeller saved the whales, by making “Coal oil” (Kerosene) for our lamps, so cheap and consistent and impurity-free (standard) as to make it relatively safe and easily affordable to use widely, allowing folks anywhere to see as they wanted without the sun. This also happened to end the market for whale oil, saving those magnificent creatures. The wildly and near-explosively inflammable contaminant removed from lamp oil, “petroleum distillates”, became gasoline to power motors, and thus to create a revolution in sanitation: no more poop/whizz filled streets and resultant disease. Other useful stuff came out of the refining process, to pave streets, lubricate machines, and seal roofs. The invention of petroleum pipelines made it safe to move massive quantities of combustible products around, safely and predictably. Oil thus powered, illuminated, and lubricated civilization.

Again, in the span of one productive lifetime.”