As measured by mass evacuation of cities, yellow fever provoked more fear and panic than any other epidemic disease in US history. This chapter concentrates on two of the most devastating epidemics in US history, yellow fever in Philadelphia in 1793 and in Memphis in 1878. Despite different times, medical ideas, and cultural horizons, their socio-psychological effects were similar: they began in chaos and with acrimony, but quickly sentiments turned, sparking abnegation and compassion that united these cities across ethnic, class, and racial boundaries. In both cities, the protagonists of the new waves of compassion were young men, and in Memphis yellow fever relief centred on established men’s social clubs as well as creating new ones.