William Graham Sumner was known to have infused the idea of American superiority based on International or Social Darwinism. Sumner was a writer and thinker of the gilded age. He developed his theory of Social Evolution after being exposed to Darwin's works. He published a pamphlet called "What Social Classes Owe to Each Other". His premise was that the different classes don't owe each other anything. This work soon became highly influential in the society of his day.