Three major Protestant missionary organizations—the Company for the ropagation of the Gospel in New England (the NEC, founded 1649), the Society for the Propagation of the Gospel in Foreign Parts (SPG, founded 1701), and the Society in Scotland for Propagating Christian Knowledge (SSPCK, founded 1709)—all played significant roles in Christianizing and civilizing the inhabitants of British North America. The New England Company had the longest history and is the oldest Protestant missionary organization. The Society for the Propagation of the Gospel in Foreign Parts sent no fewer than three hundred missionaries to America between 1701 and 1783. While the NEC and the SPG have received scholarly attention, the Society in Scotland for Propagating Christian Knowledge has been virtually ignored.

The American revolution caused the Anglican churches in America to separate from their parent body: the Church of England. This threw the Episcopalians upon their own resources to rebuild their church. In the process of reorganization, the former Anglicans accomplished an ecclesiastical revolution in respect to episcopacy. For the first time since the Norman Conquest in 1066, the Episcopalians in America made a bishop of a major religious body the elected official of a convention of clergy and laymen. In the second place, the office of bishop in a major denomination was completely separated from the state for the first time since Emperor Constantine officially recognized Christianity in 313 A.D.