The issue of equity is an important thread running through a century of Yearbooks of the National Society for the Study of Education (NSSE). Although we tend to think of equity in the schools as a relatively recent issue, it was a major concern as early as 1916. This chapter analyzes how authors of NSSE chapters conceptualized and wrote about equity in U.S. schools.Equity denotes equality of educational opportunities and outcomes for all students. Although much has been made elsewhere of the difference between equity defined in terms of formal inputs to schools and equity defined in terms of outcomes, a more inclusive definition is a better match for the breadth of the literature surveyed. If schools achieved this ideal state of equity we would find the following relationships: weak or nonexistent correlations of indices of social class (SES), race, and ethnicity and student educational outcomes such as attainment or performance; few schools segregated by poverty in which the quality of teachers and resources is inferior to that of other schools where students come from richer families; no differences in class, race, and ethnicity according to track and ability group membership within schools; and, finally, no correlations between social class background and academic status differences within classrooms so that those children who are seen as good students by the teacher and their classmates are not especially likely to be from middle-class families.Achieving equity through intervening in the schools alone is difficult because in many ways schools reflect and mirror inequities in the larger society. Some have argued that schools actively reproduce the inequalities of the larger society. In contrast, others have seen the school as receiving students who are unequal in their potential to succeed because of genetic factors or because of home and community