The social revolution is usually overlooked in the remembrance of the Spanish Civil War. This study analyzes the collectivizations in the agricultural sector, industry, and service companies based on a wide-ranging and partially difficult-to-access source material, as well as the proponents of "libertarian communism," their opponents, and the significance of both in the republican coalitions. The analysis of developments and structures highlights the historical problems, manifestations and shortcomings, spread and enforcement, decline, and end of the anarchist attempt at participatory democratization of the economy and society in Spain during the Civil War period.