This study explores the history of Portuguese ceramics and private collecting during the first half of the 20th century. It analyses the trajectory of João Maria Ferreira as a collector, and how his assemblage became one of the largest collections of Caldas pottery – comprising over 2,000 pieces – and his subsequent desire for public engagement. The methodology includes interviews with the collector (conducted in 2019), the analysis of documentary sources, and a collection inventory initiated in 2013. The collection is notable for Francisco Elias’ miniatures, as well as works by Manuel Mafra and Rafael Bordalo Pinheiro, demonstrating how Ferreira’s acquisition practices helped document the history of the factories and ceramic workshops of Caldas da Rainha. Furthermore, the case studies of three other collectors – Alfredo Lucas Cabral, Artur Maldonado Freitas, and António Capucho – illustrate how these entrepreneurs transformed their private collections into collective heritage. The study concludes that the shared ambition for public fruition validates the importance of bridging the gap between private collecting of the public sphere to enhance the valorization of national art history.