At the end of the nineteenth century, a small group of American students launched a student mission movement that eventually recruited and helped to deploy more than twenty thousand missionaries over a period of about half a century. The story of the Student Volunteer Movement (SVM) has been often recounted, but never in relationship to the colossal tragedies of the Great War. This is surprising, since the war challenged in fundamental ways both the premises and the practices of the Protestant missionary crusade. A Christian civilization's claim to moral superiority was savaged by the European war. International cooperation among Protestant denominations and missionary organizations received a devastating setback. The war crushed the cheerful hopes of the Social Gospel, that liberal alliance between the kingdom of God and American culture. The identification of the missionary with national causes in wartime led to a serious loss of credibility for missions in the decade after the war. This confusion of crusades, among a generation of disillusioned crusaders, dealt the Student Volunteer Movement a blow from which it never recovered. The End of the Crusade looks at the development and eventual decline of the SVM, chronicling the disillusionment felt by student volunteers as they were compelled to leave the SVM and enlist in a different crusade, the Great War.