How do you compare a free market to Nazism? Robber Barons is a lie made up by the Marxists. They still vilify the wealthy as Robber Barons, perhaps you are on the wrong website?
Give one example of a Robber Barron, I can give numerous examples of govts that followed Darwinism and millions were murdered because of it.
My point is that Darwinism was used to promote some good here in the United States. And it was also used for evil purposes in Europe. Darwinism itself as a construct in social policy, in how individuals react to each other, is neutral in regards to good and evil. Americans used it to great a great thriving economy, while Europeans used it to create murder. I guess the difference is in the mindset of Americans compared to Europeans.