First introduced in 1965, the Elementary and Secondary Education Act (ESEA) has evolved over time, emphasizing education reform priorities that mirror the changing national education policy conversation. The most recent iteration of ESEA, as amended by the No Child Left Behind Act (NCLB), was enacted in 2001. It emphasized improving outcomes for all students regardless of their race, language, or disability, with a strong focus on accountability for teachers, schools, and districts. A decade later, ESEA is again due for reauthorization. This Pocket Guide will assist policymakers and educators as they consider changes to this law--particularly changes related to ensuring a highly effective teacher in every classroom. (Contains 3 figures.) [For related reports, see "School Turnaround: A Pocket Guide. Reauthorizing ESEA: Making Research Relevant" (ED530797) and "Students with Disabilities: A Pocket Guide. Reauthorizing ESEA: Making Research Relevant" (ED530795).]