The aim of this work is to undertake a historical study in order to broaden knowledge based on the proposed investigation into the Formation of the Nation State from the perspective of the Piauí jurist and politician Antônio Coelho Rodrigues, demonstrating how it is possible to see the formation of the Republic from another angle and understand that the project of a Republic idealised by the positivists was not fully constituted in Brazil at the end of the 19th century. In this way, our proposal is to look beyond the ideological, economic and social transformations that took place in Brazil at the end of the 19th century to Coelho Rodrigues’ conceptions of republican Brazil. In this context, we emphasise the importance of Political History as the starting point for our reflection.