In this article, we intend to illustrate the notion, practice, and evaluation methods and results related to building an effective, efficient, and equitable early care and education (ECE) system. We point out the dominant approach, in practice and evaluation, of focusing on a single ECE program to improve ECE, propose a model of developing an ECE system that is effective, efficient, and equitable, and illustrate how to use empirical evaluation data to facilitate and validate the building of such a system. Implications are discussed for improving ECE systems and ultimately child outcomes. (author abstract)