Shortly after her brother was killed in battle in World War I, Katharine McLennan decided she wanted to join other young women overseas as a nurse's aide in the military hospitals. Her father, however, would not hear of his youngest daughter tending to sick and dying soldiers. Frustrated by his refusal, Katharine enlisted the help of her sisters to convince him to let her go to France with the Red Cross Society, the Secours aux Blesses Militaries. J.S. eventually relented and she headed overseas in the spring of 1916.