"Equality of Educational Opportunity," also known as the Coleman Report, sought answers to two burning questions: (1) How extensive is racial segregation within U.S. schools?; and (2) How adversely does that segregation affect educational opportunities for black students? In answering the first question, James S. Coleman and his co-authors documented the de facto segregation found in all parts of the United States, including the South, where the Supreme Court had declared de jure segregation unconstitutional in "Brown v. Board of Education" (1954). Regarding the second question, Coleman reported that families were more important for learning than were school resources, and, further, that school resources varied more by region than they did by a school's racial composition within any specific region. Yet Coleman also noted that the composition of a student's peer group was more important for learning than any other school-related factor, a finding used by the Johnson and Nixon administrations to reinforce their strenuous desegregation efforts in southern states. Today, questions about the effects of changes in housing patterns and recent Supreme Court decisions that weaken desegregation efforts remain central to discussions of educational opportunity and racial achievement gaps. How can two questions that seem so similar have such different answers? The explanation is in the changing demographic composition of the schools: the percentage of students who are white has declined dramatically over the past 50 years, while the percentage of students who are black has changed very little. In this article, the author details these changes, and inquires into the consequences for achievement of the racial segregation that still persists. [This article is part of a new "Education Next" series commemorating the 50th anniversary of James S. Coleman's groundbreaking report, "Equality of Educational Opportunity." The full series will appear in the Spring 2016 issue of "Education Next."]