Illinois' youngest children--nearly half-a-million infants and toddlers--are at the leading edge of a demographic transformation. They herald a state, and a nation, more diverse with respect to race/ethnicity, country of origin, language, and family type than at any time in recent history. Yet, this is a generation notable for marked inequities, with disturbing proportions facing severe disadvantage that imposes both immediate and lasting threats to well-being. Significant numbers are born into families without the financial resources to promote their development; disparities by race and Hispanic origin persist; public policy responses have been slow to materialize and, where they exist, often serve only a fraction of the children in need. This report is a demographic portrait of the nearly half-a-million infants and toddlers in Illinois. The following are appended: (1) Demographics; (2) Child Health and Development; (3) Parental Well-Being; (4) Neighborhood and Family Context; and (5) Public/Private Supports.