In this paper I will examine Spencer’s most important disciples in the United States in the latter part of the nineteenth century, including the historian John Fiske, the journalist Edward Youmans, and the Protestant figures who were inspired by his religious thought. My goal is to see what attracted these thinkers to Spencer, and whether or not they were all attracted by the same aspects of his System of Synthetic Philosophy. Fiske was interested in Spencer’s cosmic evolution and built an entire philosophy around it. Youmans, who worked for Appleton, was the driving force behind the International Scientific Series, and he intended it to be a vehicle for disseminating Spencer’s ideas throughout the world. American Protestants found Spencer’s Unknowable and his goal-directed evolutionary theory to be adaptable to Christian theology. I will also examine how Spencer’s ideas were transmitted to the American public and how the means of transmission may have affected how he was understood.