A history of social justice in education is useful for at least two reasons. First, competing notions of social justice in education are not new. Tension between a belief in assimilation and the ability of individuals to climb the meritocratic ladder and the belief in a respect for cultural and linguistic differences and a flattening of the racial, ethnic, and linguistic hierarchy has existed since the start of the common school system. Second, current educational reformers and others appropriate history and memory to justify certain avenues to social justice. Examining the history of social justice in education, therefore, not only illuminates what transpired but also provides a portrait of how, why, and the end to which the history of education is managed for contemporary purposes. The first part of this article examines the promise of assimilation or the lack thereof in American educational history in order to assess if this promise was genuine, desirable, or fulfilled in the educational experiences of American Indians, Mexican Americans, Chinese Americans, Japanese Americans, and African Americans. The focus is on the battle against segregated schooling, but the desire for desegregation and assimilation should not be understood as synonymous. The pairing is used here to highlight how those groups considered assimilable and those considered unassimilable were deliberately segregated by White communities and school boards. The second part examines how these racial and ethnic groups created and/or fortified separate schooling experiences that directly contradicted the assimilationist vision of social justice and how their efforts are understood by historians. Historical actors, much like the Leadership for Social Justice Special Interest Group, believed that cultural and linguistic integrity and maintenance form the basis of social justice and that collective rather than individual advancement was the proper marker for gauging success. Historians, however, like other scholars, debate whether the efforts of these historical actors furthered or hindered the pursuit of social justice in education. (Contains 9 notes.)