AbstractA vigorous Protestant left existed throughout the first half of the twentieth-century in the United States. That Protestant left was the left wing of the social gospel movement, which many historians restrict to the pre-1920 period and whose radical content is often underestimated. This article examines the career of one representative figure from this Protestant left, the Reverend Harry F. Ward, as a means of describing the evolving nature and limits of social gospel radicalism during the first four decades of the twentieth century. Ward, the main author of the 1908 Social Creed of the Churches, a longtime professor at Union Theological Seminary (UTS) in New York, and a dogged activist on behalf of labor and political prisoners through his leadership of the Methodist Federation for Social Service, sought a new social order from the early years of the century through the Great Depression of the 1930s. This new order would be the Kingdom of God on earth, and, in Ward's view, it would transcend the competitive and exploitative capitalism that dominated American society in his time. Before World War I, Ward worked to bring together labor activists and church people, and, after the war, he shifted his work toward less expressly religious efforts, while continuing to mentor clerical protégés through his teaching. Ward's leftward trajectory and ever-stronger Communist associations would eventually bring about his political downfall, but, in the mid- 1930s, he remained a respected figure, if one more radical than most, among American Protestant clergy. Organic links tied him and his politics to the broader terrain of social gospel reform, despite the politically driven historical amnesia that later would all but erase Ward from historical memory.