How did the Sherman Antitrust Act affect industrialists like Rockefeller?

At a time when businesses were running separate of
government action and when industry controlled so much of American life, the Sherman
Antitrust Act was a significant piece of legislation in attempting to control that which
existed as uncontrolled.  The so- called "Titans of Industry" such as Rockefeller, J.P.
Morgan, and Andrew Carnegie operated in a realm outside of politics, social sensitivity,
as well as any other element.  These individuals were considered to be the "best and the
brightest," and were also the most powerful because, simply put, no one could control
them.  The Sherman Antitrust Act was one of the first steps to ensure that government
could prove to possess some level of control over these forces.  In ensuring that the
idea of illicity monopolies harm the American free market system, and laying down
prerequisites that established business cartels and a crushing of competition, the Act
was significant in that it represented a form of government check on business
practices.  It showed Rockefeller and Standard Oil, as well as other conglomerates, that
they could not influence the marketplace in order to consolidate their own power.  The
elimination of sitting on other companies' boards, for example, and targeting behavior
that "unfairly tends to destroy competition itself" is where the greatest impact of this
legislation was felt by those in the position of economic power, such as
Rockefeller.