A generation ago Americans undertook a revolutionary experiment to redefine marriage. The results of this experiment separating marriage from childrearing are in, and they are bad news for children and for the country as a whole. The family upheaval has hit African-Americans especially hard. We forgot what American marriage was designed to do: it ordered lives by giving the young a meaningful life script. It supported middle-class foresight, planning, and self-sufficiency. And it organized men and women around The Mission—nurturing their children's cognitive, emotional, and physical development. It is The Mission that separates middle-class kids from their less-parented and lower-achieving peers. In fact our great family experiment threatens to turn what the founders imagined as an opportunity-rich republic of equal citizens into a hereditary caste society.