This chapter explores the rise of modern business enterprises with multi-business units and managerial hierarchy and the structural changes of big business. First, this chapter considers the historical background of the birth of the modern business enterprise in Germany. Next, based on cases in key industrial sectors such as the iron and steel, chemical, electrical engineering, machine, and mining industries, changes in organizational structures and their characteristics are considered concerning the scale expansion of companies and regional dispersion of business units, vertical integration, and diversification. Moreover, this chapter considers the establishment of the central office concerning the functional separation of the directors’ duties, the reform of the accounting system, and the establishment of the executive’s representative organization and committee organizations. Furthermore, issues concerning the appearance of salaried managers and the rise of managerial enterprises are clarified concerning the type of enterprises in Germany, the retrocession of owner–managers, and the rise of salaried managers from the comparative viewpoint with the United States.