Aucun établissement n'est affilié à ce groupement.
- The term is a portmanteau of the St. part of St. Mark's, St. Paul's, and St. George's, then part of Groton, an extra t, and then ended with Middlesex. The St. Grottlesex schools were founded in the mid- to late nineteenth century for well-to-do Episcopal Church boys (excepting nondenominational Middlesex, founded in 1901), and were consciously styled as the American equivalent of famous English public schools. In contrast, the Academies, notably Andover, Exeter, Milton, and Deerfield, were generally founded in the late eighteenth century as places to "combine scholarship with more than a little Puritan hellfire" and, originally, were often the first educational step in preparing men for the Puritan ministry. The St. Grottlesex schools retain an aura of preppy establishment.