In its first twenty-four years, 184 branches opened in several Spanish provinces, as well as Cuba, El Salvador, the United States (US), Guatemala, Honduras, Mexico, Nicaragua, Puerto Rico, Santo Domingo, Uruguay and Venezuela.

[4] For administrative operations, the schools established a rigid discipline, governed by a document entitled, "Rules of Procedure, Statutes, Circulars and Articles", from its official magazine, La Balanza ("The Balance").

[citation needed] On October 12, 1921, he developed the Hispanic-American-Oceanic Union (UHAO), symbolized by a flag with the seven colors of the rainbow and the Basque Oak tree of Guernica.

[citation needed] Nicaraguan revolutionary and politician, Augusto César Sandino, was one of the best-known followers of Mateo's "Luz y Verdad" ("Light and Truth") manifesto of 1931.

At the time of Mateo's death on December 6, 1935, it was revealed that he had left directorship duties of the school to his wife, Maria Mercedes Riglos Cosis.