The period covered in this volume of Nuevo Leon in the 20th century is what we have historically characterized as "openness and globalization of the State""; during this time, there were significant changes in almost all politics, economy and culture. In the twentieth century, the state of Nuevo Leon, Monterrey specifically, had significant transformations, as it was presented in the two previous volumes of the collection. The importance of this period is that the changes were not only reactions to the domestic environment, but also to the intense and dynamic liaisons that resulted from Nuevo Leon's integration into the globalization process. The main institutions of the State were shaken and became engaged into a process that will undoubtedly continue in the following decades of the 21st century. The texts of this volume are from authors such as Victor Lopez Villafane, Juan Zapata Novoa, Sergio Elias Gutierrez Salazar, Maria de los Angeles Pozas, Anne Fouquet Guerineau, Lylia Hernandez Palacios and Carolina Farias Campero.