This paper presents an overview of the work of sisterhoods in the parochial schools in Massachusetts from 1870 to 1940. The needs of the sisters as members of religious communities and their needs as professional educators are pointed out, and a distinction is made between the operation of parochial schools owned by a religious community and those where the sisters served as employees. Developments in building and staffing the schools are described, including the reasons for the proliferation of parochial schools in Massachusetts during the 1800s. Conflicts between public and private schools due to differences in curriculum, methods, and theory are delineated. Reasons for opposition to parochial schools are described. Characteristics of the parochial school faculty, their relationship with the diocese, and their reaction to the emphasis on professionalism after 1890 are cited. (FG)