Spencer proved to be a popular figure in the 1880s primarily because his application of evolution to areas of human endeavor promoted an optimistic view of the future as inevitably becoming better. In the United States, writers and thinkers of the gilded age such as Edward L. Youmans, William Graham Sumner, John Fiske, John W. Burgess, and others developed theories of social evolution as a result of their exposure to the works of Darwin and Spencer.