This article identifies themes of continuity and change related to the well-being and development of infants and toddlers. The author describes several particularly striking changes over the last 25 years of research and practice in early childhood development. (1) The infant-family field has grown in many professions from a marginal area to a central concern. (2) Collaborations within areas of research, within the provision of services, and between them have become common among infant-family professionals. (3) Programs of all kinds that serve infants, toddlers, and families have proliferated exponentially at all levels of prevention and intervention. (4) There is a growing awareness and appreciation of the salience of the relationships that practitioners and families create.