In 1739 the Governor José Antonio Manso de Velasco made important adjustments, improving and properly supplying the fortress and constructing between the river and the small Laguna de Rayenantú behind it, deep ditches, that turned the enclosure into an island, and increasing its population to serve as its garrison for the defense of the region and the wooded valleys of the southern mountainous area. Governor Antonio de Guill y Gonzaga obtained the title of "Villa" for the town in 17652, but the wars with the Indians did not allow it to make any progress even though it constituted the refuge of the extinguished towns of Coya, Monterey and San Jerónimo. It was also one of the towns that was burned in 1821 at the order of Vicente Benavides the rebellious royalist. It was later ruined in the earthquake of the February 20, 1835. As a result of this last disaster it was six years later moved to its present more suitable location.
Santa Juana was head of the Department of Lautaro between 18413 and 18654. On May 30, 1865, Coronel became the new capital of the department4. With the Law of Independent Communes, December 22, 1891, the Decree of Creation of Municipalities was promulgated3, with which created the Municipality of Santa Juana, in which Santa Juana administers Santa Juana, Santo Domingo and San Jerónimo, whose boundaries were determined by the decrees of November 13, 1885, March 29 and December 1, 1886.
References
^ Montero de Tortora, Lo que fue Catirai y es Santa Juana de Guadalcazar. pg. 6,7
^ I. Municipalidad de Santa Juana, 2007. Antecedentes Históricos. Estudios realizados por la Universidad de Concepción en los empalzamientos del Fuerte Santa Juana de Gualdalcázar. Disponible en http://www.santajuana.cl/Fuerte%20Historico.asp
Montero, Elsa; Lo que fue Catirai y es Santa Juana de Guadalcázar. Santiago: Editorial Universitaria, 1967. 24 p. , Ubicación: Sección Chilena 10;(1010-26), N° sistema: 603103
