Nationalism is a concept developed to understand a phenomenon typical of the 19th century: the rise of a certain feeling of belonging to a culture, a region, a language and a people (or, in some of the nationalist arguments, to a race), having first appeared in France under Napoleon Bonaparte and in the United States of America. This phenomenon began to be assimilated by the political forces that had absorbed the Enlightenment ideals of rejection of the Old Absolute Regime and that sought the construction of a national state with a democratic and constitutional bias, in which its members were citizens, not subjects of the king.
In this sense, the national sentiment of the 19th century reached the condition of political ideology. Unlike the European national states that were formed in the sixteenth and seventeenth centuries, the national states of the 19th century identified their sovereignty in the contingent of citizens that made up the nation, and not in the figure of the monarch. For this reason, the tendency towards the republican political regime became common during this period.