Final answer:
The rapid settlement of the West was influenced by various events and policies; however, growth of a consumer culture was not a direct factor but an outcome of industrialization in urban centers.
Step-by-step explanation:
The factors that led to the rapid settlement of the American West between 1860 and 1900 include the California Gold Rush, the completion of the Transcontinental Railroad, the Homestead Act, and various demographic, economic, and political pressures. Groups that significantly participated in this westward migration were predominantly White American farmers, European immigrants, particularly from Northern Europe, and African Americans escaping racism in the South. Government policies and the establishment of forts aided the settlement and provided support against conflicts with local native tribes. However, the growth of a consumer culture in the United States at the close of the nineteenth century is not directly related to the westward migration but rather an outcome of the industrialization processes happening in urban areas.