School-based management (SBM) and its counterpart, shared decision making, raise traditional questions about power, representativeness, decentralization, and professionalism. This paper turns to history to provide a framework for untangling the issues that have come to the fore in current debates about power and shared school governance. In a historical look at school labor relations and the governance of education, the paper suggests that, in many ways, teacher associations have come full circle. A review of historical records supports two propositions: (1) Teacher unions have initiated and supported significant social change; and (2) unions, along with other stakeholder groups, play an important role as guardians of democratic processes. The paper revisits the objectives of teacher organizations and issues of educational decision making within a historical context, placing current debates against a backdrop of the struggles and ideals that shaped the earliest teacher unions. The formative union years, from the late 1800s to the mid 1920s, provide the framework for the historical discussion. A guiding assertion is that teacher unions have brought about and should continue to bring about radical change in education, but that they should take a historically informed approach to teacher involvement in school management. There is ample evidence that unionism and shared governance can and should coexist. Lessons from the history of teacher unionization are offered as guidelines for restructuring labor relations in the age of site-based, shared decision making. Two figures are included. (Contains 42 references.) (LMI)