This study provides new evidence on the advance of literacy in Spain during the period 1860-1930. A novel dataset, built with historical information from the Spanish population censuses (over 8000 municipalities), enables this process to be described in detail from the end of the "Ancien Régime" to the Second Republic. The study thus presents stylised facts at a very low level of geographic aggregation, thereby permitting a closer examination of the main patterns. Overall, spatial differences in literacy were sizeable during the whole nineteenth century. Furthermore, these disparities were only significantly reduced between 1900 and 1930 when the growing demand for these basic skills was met by stronger government intervention.