This chapter traces the legal, legislative, and political history of the Elementary and Secondary Education Act (ESEA). Focusing attention on the various related educational reform movements, it discusses the federal role in education policy in the context of its influence on ESEA and the legislation's related amendments. Also, the authors examine the complex issues involved in responding to the changing and more complex needs of underserved schoolchildren through federal policies and accountability provisions. They make the case that the increased federal role in public education has pointed to serious limitations in understanding how to best address the educational challenges faced by traditionally disadvantaged schoolchildren. The authors argue that the current accountability requirements under ESEA and the No Child Left Behind Act (NCLB), although a step in the right direction, were developed from a theoretical perspective and lacked an understanding of the complex issues involved in serving disadvantaged schoolchildren. In addition, they contend that a thorough understanding of the role of state and local educational contexts in serving disadvantaged schoolchildren is needed to guide policymakers, and they encourage educational researchers to develop more effective policy interventions. [This article represents Chapter 3 of "The Elementary and Secondary Education Act at 40: Reviews of Research, Policy Implementation, Critical Perspectives, and Reflections," "Review of Research in Education," v29, 2005 (EJ748131).]