This article analyzes the Chilean schooling process during the period in which the State sought to institutionalize universal access to primary education. This goal, contained in the compulsory school law of 1920, was challenged by desertion and lag in school. Although the educational coverage was extensive in terms of school enrollment, the level of schooling was very low. In order to explain this phenomenon, the article distinguishes between the extension of coverage and the expansion of schooling, identifying internal imbalances in the schooling process. It argues that, despite the social demand for education, social policy did not prioritize school attendance and children’s permanence within the educational system. The results obtained discuss the assumption that links the expansion of public education to a broader social inclusion agenda framed within the welfare state, which its triumphalist emphasis has obscured its excluding dynamics.