In the introduction to A Little Commonwealth, his 1970 work on family life in Plymouth Colony, John Demos observed that this kind of study had not gained “a wide following among working historians” (p. vii). Most historians, he said, still preferred to concentrate on large social units such as region, class, or party and leave the family, “the smallest and most intimate of all group environments,” to anthropologists, sociologists, and psychologists (p. viii). Today, almost twenty years later, no such statement can be justified. Since 1970, the new social history, including family history, has grown dramatically to become a significant force in contemporary historiography. Thus, in his latest book, a collection of essays on the family and the life course in American history, Demos offers no special pleading for his subject and simply assumes his readers will understand and accept its importance. Demos now writes with the quiet confidence of one who is working well within the mainstream of historical scholarship.