Abstract This essay examines the expression of emotional states by frontline medics in the American Revolutionary War to understand how doctors felt about their role as caregivers during the Canada Campaign of 1775–76 and the Sullivan-Clinton Expedition of 1779. The first section queries how surgeons managed the emotional strain of caring for wounded and sick soldiers during the Invasion of Quebec. The journals of two doctors who expressed resentment and grief towards the officer corps during the invasion, Samuel Fisk Merrick and Lewis Beebe, are considered. In the second section, the essay focuses on the role that expressions of enthusiasm, particularly what scholars term settler colonial optimism, played in during a total war. Here another pair of doctors, Jabez Campfield and Ebenezer Elmer, afford insight into the hope surrounding land-grabbing felt by medics during the army’s genocidal campaign in western New York and Pennsylvania.