The Third Republic is the Liberal Republic (1870-1924) that is created by a constitutional mutation from the Second Republic. This Republic is characterized by the expansion of the right to vote and by a new liberal political atmosphere. During this period of the Liberal Republic the supremacy of the legislative function is imposed even after the 1891 civil war. The new expressions of Chilean constitutional law in the works of Roldan and Letelier is explained. Also the relationship between the social question and liberal constitutional republicanism is explored. The new political actors such as new political parties and the coups d’etat that destroyed the Third Republic is also a part of this section.