In this brief, we introduce the science demonstrating that early childhood is the most critical time in brain development, laying the foundation for all future learning. We articulate the goals of the Kansas Children’s Cabinet’s Blueprint for Early Childhood and how the three building blocks of Early Learning, Healthy Development, and Strong Families contribute to a child’s school readiness. We summarize the research on the short-, medium-, and long-term impact of early childhood programming, including cost avoidance studies which consistently demonstrate that high-quality early childhood care and education has a return on investment of 7-13%. (author abstract)