This report examines the role of state education agencies in implementing NCLB, their capacity and expertise to meet its requirements, and how this capacity varies across states, including how states are meeting the increased financial and human resource demands of NCLB and how they are working with schools and districts identified for improvement under the law. A fundamental question is whether or not the state agencies have the resources, knowledge, and organizational capacity to intervene on the scale demanded by NCLB. In addition, the report traces the development of the state role in education and how this shaped both the structure of the educational system and the functions that state educational agencies perform. This historical development has implications for the ability of state agencies to meet the NCLB requirements since it establishes the existing conditions that states operate under. The report uses a case study methodology and data collected from six states (Arizona, California, Georgia, Illinois, New York, and Virginia) that are part of an ongoing study of NCLB.