"Energy" in the form of "oil" was the foundation of John Rockefeller's vast wealth.
Mr. Rockefeller's Standard Oil company was a monopoly. He argued that his monopoly was good for the consumer, the Federal government disagreed.
A hundred+ years after the breakup of Standard Oil the argument over "monopolies" tends to only occur in academic circles. The Library of Congress has more information about the breakup of Standard Oil for the curious ...
An unintended consequence of the breakup was making John Rockefeller even MORE wealthy.