The paper highlights the context and the main points of the speech given by Max Weber at the International Congress of Arts and Science in St. Louis in September, 1904. It analyzes Weber’s views on the dynamics of social change as presented by the German classic in the shape of the comparative historical sociology of the European and American versions of modernity. The first part of the article covers the background and the most significant episodes of the trip to the United States undertaken by Max Weber and his wife Marianne. The second part of the article elucidates the main points of Weber’s speech in St. Louis. The third part examines the observations and conclusions of the specifics of American modernity made by Weber through his direct acquaintance with life in the United States. In conclusion, the paper proposes a brief analysis of Weber’s contribution to the development of historical sociology’s ideas about the nature and pathways of Western modernity.