Investigations of the structure, rule systems, and histories of black families in rural Mississippi, Chicago, New Orleans, East Texas, and Southern California have shown the presence of well-integrated, multigeneration, multihousehold, bilateral extended families in varying U.S. social environments. These families, while varying in detail, share structural features: an elderly moral leader, associated household heads, a shifting body of young members, and a geographical focus, often including a burial ground. Behaviorally, other features include: reciprocal economic aid, child fosterage, and care for the sick; exogamy, attendance at funerals, and often, special reputations. Adaptively, these families have aided survival in deep rural poverty, in disorganized ghettos, and in the search for upward mobility; at times, they form multicommunity networks. Based on descent and cooperation rather than marriage and household property maximization, black extended families differ sharply from white analogues, but have many Caribbean and African correspondences. Black family norms need legal recognition and support, e.g., in rules of adoption, to reduce injurious discrimination against black people in U.S. family law and social practice. (Author)