The American culture is mainly composed of emphasizing individual value, pursuing democracy and freedom, worshiping development and competition and highlighting rationality and practicality. Its core is individualism: to highlight personal supremacy and interests, and to pursue the ultimate realization of personal value through personal struggle and self-design. This kind of individualism, which shapes oneself and pursues individuality, has its positive significance. It mobilizes one’s enthusiasm, makes many people's wisdom and potential fully developed, and thus promotes the revitalization and development of the whole nation and country. The United States is a highly mobile society. This kind of mobility is embodied in two aspects: regional mobility and social mobility. The relatively open, free, developed transportation and adventurous tradition of the United States have led many Americans to flow from the countryside to the city, from the city centre to the suburbs, from the north to the southern sunbelt, from one city to another. The American social class is not as fixed as that of European countries, and the popularity of public education makes it possible for grassroots to move up. Many American residents, whether they are native Americans or foreign immigrants who come to the United States by sea, have a dream, namely, to change their destiny and realize their life dream through their own efforts, which is the “American Dream” that people often like to talk about.