The Fragile Families Study, a survey of 5,000 children representative of all non-marital births in US cities with populations of over 200,000, provides new evidence on the characteristics of unmarried parents and their children. Initial analyses reported in this article reveal that the typical unmarried mother is in her early twenties and cohabiting at the birth of her children. Almost one third are Hispanic and 51 per cent non-Hispanic black. The great majority of unwed parents are committed to each other and their children at the time of birth but most are poorly equipped to support themselves and their children.