The geographic distributionsGeographic distribution of species change over time as climates shift during glacial to interglacial periods. In this chapter, we describe the history and biogeography (distributionDistribution through geographic space and geologic time) of red spruce (Picea rubensRed spruce ()) beginning with the last glacial maximumLast glacial maximum and continuing to the present. While the central and southern Appalachians are the focus of the book, this chapter includes the entire range of red spruceRed spruce (), both past and present, highlighting the biogeographic variation throughout the species’ range and deepening the knowledge of how red spruceRed spruce () dispersed to the central and southern Appalachians. The variation in biogeography of red spruceRed spruce () is a representation of the evolutionary process of adaptation to local factors. We also highlight how past human activities, such as pre-industrial loggingIndustrial logging, and current environmental factors, such as topography and cloud immersion, influenced the current distributionDistribution of red spruceRed spruce (). Understanding the drivers of red spruceRed spruce () occurrence is critical for management and restoration of spruce-fir forests in the Eastern U.S.