The development of modern educational systems radically altered the way knowledge and skills were transmitted. Yet, while elementary schooling rapidly expanded in late 19th and early twentieth centuries, secondary education struggled to fnd its way. This was also the case in Spain where, despite a growing demand, the provision of public secondary education during the second half of the 19th century was rather limited. As a result, private education, and especially that promoted by the Church, rushed to fll in the gap. Using a new database with municipal-level data, we examine what drove the expansion of private schools. As expected, demand-pull factors were critical. Still, the interplay between local forces and private agents should not be overlooked, especially as the State lacked the fnancial muscle and political will to broaden access to secondary education, whereas the Church was searching for a niche from which to consolidate its position in the nascent liberal society.