The simplest and most widely held definition of Social Darwinism is the application of concepts of biological evolution to social and moral development. More specifically, it is social evolution through "survival of the fittest" in a "struggle for existence" in which the strong prevail and the weak are defeated and disappear. Social Darwinism theory has been used to explain the history of Europe and, more particularly, the United States in the Victorian era. At the core of Social Darwinism is the idea of evolution, which was developing from the intellectual environment of the mid-nineteenth century West, and was adapted by people in that environment to meet their own intellectual needs. Although explanation of Social Darwinism is often over-simplified, this author states that the concept may yet be valuable as a historiographical subject that allows an accurate portrayal of Victorian history, while demonstrating to students how widely-accepted generalizations sometimes frame the understanding of history. In this essay, Versen illustrates the concept of Social Darwinism using the writings of Herbert Spencer, Charles Darwin, Andrew Carnegie, Richard Hofstadter, William Graham Sumner, Roger Bannister, and Donald Bellomy. (Contains 48 notes.)