Urban dynamics in recent years show a tendency that cannot be ignored in terms of the impacts that they induce, with regard to many companies, especially big companies, that are settled in the downtown districts of the main cities, where economic spaces are blended with urban spaces. This study, therefore, aims to investigate the sustainability of cities by using the specific perspective of their relationship with the companies’ urban settlements. Some questions in the present work are discussed: What advantages derive from the firms’ settlements in downtown areas? What is the impact on urban geographies? What role does urban policy play in this process? How do cities perceive this large business settlement? To answer to these questions, a model of dynamic equilibrium, referred to as the public–private relationship, is provided. The analysis starts from the context of the city as a commercial space, then identifies the determinants of the establishment of businesses in the city centers and the mediating function of politics in this urban morphogenesis. Case studies from the USA on large companies returning to urban centers complete the analysis.