How was social darwinism used to defend and support the new industrial economic order?

In the United States, the theory of Social Darwinism was
used in the "Gilded Age" to justify the fact that some people were gaining immense power
and wealth while others remained in poverty.  This growing stratification of wealth was
occurring as a result of industrialization.

The theory of
Social Darwinism argues that some people are more "fit" than others to succeed in a
competitive economy and society.  In this competition, the fittest people rise to the
top and the less fit sink.  This meant that anyone who was rich during this time had
(the theory goes) gotten that way because they were more fit than others.  In other
words, they were simply better and so they deserved to be rich while the others deserved
to be poor.  This justified the growing inequality because it said that that inequality
was natural and not the result of bad actions on the part of the
rich.