In 1900, Swedish design reformer and social theorist Ellen Key published ''The Century of the Child,'' presaging the coming century as a period of intensified focus and progressive thinking around the rights, development and well-being of children. Taking inspiration from Key-and looking back through the twentieth century-this volume, published to accompany an exhibition at The Museum of Modern Art, examines individual and collective visions for the material world of children, from utopian dreams for the ''citizens of the future'' to the dark realities of political conflict and exploitation. Surveying more than 100 years of toys, clothing, playgrounds, schools, children's hospitals, nurseries, furniture, posters, animation and books, this richly illustrated catalogue illuminates how progressive design has enhanced the physical, intellectual, and emotional development of children and, conversely, how models of children's play have informed experimental aesthetics and imaginative design thinking-engendering, in the process, reappraisals of some of the iconic names in twentieth-century design and enriching the unfolding narrative of modern design with other, less familiar figures. Divided into seven sections-''New Century, New Child, New Art''; ''Avant-Garde Playtime''; ''Light, Air, Health''; ''Children and the Body Politic''; ''Regeneration''; ''Power Play''; and ''Designing Better Worlds''-''The Century of the Child'' focuses on individuals and projects that represent innovative and comprehensive contributions to design for children.