Social network analysis is an increasingly common tool for historians seeking to understand the interrelations between individuals. A significant concern, however, is how we might measure changes within networks over time and between periods. Historians have favored examining the network as it stands at particular points in time. However, this approach fails to capture the instability within networks and does not incorporate the perceptions of contemporaries. One solution is to integrate network data into a time series that is built around conceptualizations of the “network memory.” In a case study on John Pinney’s late eighteenth-century Nevis–Bristol network, I use a two-year moving total to model the lingering nature of ephemeral interactions on the memories of those involved in the plantation trade. Using this historical social network analysis as the basis for an iterative approach to the primary material, I explore what being a part of this network meant for the enslaved people on Pinney’s plantation and for the women in his family. This article demonstrates the value of the approach and highlights the ways in which historians can use it to contribute to the historiography of early modern business networks.