Robber barons, specifically Andrew Carnegie, an industrialist and John D. Rockefeller, a philanthropist, were the chosen, elite members of society according to the doctrine of Social Darwinism. Darwinism is when evolution occurs and the strongest organisms of an ecosystem survive and reproduce to outnumber the weaker, less fit organisms of an ecosystem. Similarly Social Darwinism follows the same concept, but in a capitalist sense of thought. Those who were able to exploit the Gilded Age’s laissez faire economy to their own benefit, like the robber barons Andrew Carnegie of Carnegie Steel and J. D. Rockefeller of Standard Oil, were the fittest members of society because they were able to survive in the grueling and ruthless free economy. By usurping all of the fresh yet unfit immigrants that were flowing into the States due to the rise of urbanization, these two men integrated these easily-manipulated people into their factories to augment their profits. Even further, these robber barons would often ruthlessly eradicate competition by buying out other companies to establish monopolies through the horizontal and vertical integration of production and product.