The "achievement gap" is a matter of race and class. Across the U.S., a gap in academic achievement persists between minority and disadvantaged students and their white counterparts. This is one of the most pressing education-policy challenges that states currently face. For decades, policymakers, researchers, and school reformers have sought ways in which schools could address the gap. Strategies have focused on school funding, teacher quality, student interventions and motivation, school organization, management, and climate, market competition, and school accountability to the public. Between 1970 and 1988, the achievement gap between African American and white students was cut in half, and the gap separating Latinos and whites declined by one-third. That progress came to a halt around 1988, however, and since that time, the gaps have widened. "Closing The Achievement Gap: Principles For Improving The Educational Success Of All Students" developed by the ERIC Clearinghouse on Urban Education briefly reviews the educational policies and practices whose effectiveness in closing the achievement gap has been shown. These policies and practices are presented in this paper. (Contains 15 online resources.)