Event-based mediated participatory archives, in which communities of ordinary people contribute their records to archives during collection day events represent a paradigm shift within the archival field. Applying a qualitative approach, this study investigates event-based mediated participatory archives using Bastian's communities of records and memory as a guiding framework. Using the Mass. Memories Road Show as a case study, data collection and analysis took place over three phases. In Phase I, archive supporting documents were collected and analyzed using "against the grain" historical analysis methods. In Phase II, data from the Mass. Memories Road Show digital collections were collected and analyzed using grounded theory analysis methods. In Phase III, ethnographic research data, including a direct observation and semi-structured interviews, was collected and analyzed using ethnographic analysis methods. The results of this study suggest that community participants' motivations to contribute to participatory archives are rooted in self-fulfillment while institutional archives personnel members' intentions are based in inclusive community-building. Furthermore, the contribution of records to the archives allows community participants to share personal stories that serve as evidence of their historical legacies and as affirmation of their roles in their communities. Throughout the findings, moments of connection which enable the sharing of stories are highlighted—speaking to the importance of the collection day event.