My dissertation traces aggressive masculinity’s ascendancy during the eighteenth century through the experiences of Quakers in Pennsylvania and their shifting diplomatic strategies with the Lenape. During colonial Pennsylvania’s first seventy years, elite Friends successfully governed as benevolent patriarchs using pacifist policies that promoted religious pluralism, ethnic diversity, and equitable treatment of native peoples. The political and social instability of the second half of the eighteenth century, however, eroded their ability to govern effectively without accessing the masculine role of warrior. As Quakers steadfastly upheld their peace testimony, their critics performed a version of manhood defined by racial animosity, genocidal violence, and the feminization of any other forms of masculinity. By the end of the century, Friends, facing emasculation and complete alienation from civic participation, shifted their rhetoric from comity and partnership with the Lenape to sentimental paternalism and assimilation. Doing so recast the peace testimony from an emasculating dogma into one that endowed Quakers with a distinctively “civilizing” masculinity in the eyes of their white peers.