About ten months after the founding of the Historical Society, Jeremy Belknap drafted a Circular Letter of the Historical Society, dated 1 November 1791, for the purpose of announcing the formation of the Society, defining its objectives, and particularly for soliciting historical, contributions for the library. The letter was the Society’s first publication and in many ways its most important, establishing the new organization as a repository of historical material and stating that such collections would be accessible to the public. "Belknap's vision of the Society as a private organization endowed with a public responsibility . . . was not unusual"¹ for late-eighteenth century Bostonians. As the Circular Letter stated: "Any person desirous of making a search among the books or manuscripts, may have access to them." This attitude of accessibility by the public to its intellectual heritage was a reflection of America's fight for democracy.

After stating the Society's function, Belknap indicated that collections would be published in the American Apollo, a local periodical of intellectual curiosities. Although the Society did not have a formal collecting policy, Belknap requested contributions in the following areas of colonial, revolutionary, and independent American history: town histories and genealogical records, wars and battles, personal narratives of suffering and captivities, histories of local churches, biographical memoirs, geographical, meteorological and topographical descriptions, census and vital records, modes of education, and commentaries on travel, navigation, manufacturing and commerce. The contributions could be in the form of "books, pamphlets, manuscripts, maps or plans," as well as "natural or artificial productions which may enlarge its museum."

The circular letter was sent to members, prospective members, friends, and "other gentlemen of public character"; it was later published in the American Apollo, and eventually revised and expanded for subsequent solicitations. Through repeated distribution of this circular letter and his constant personal persuasion, Belknap actively pursued the sources upon which organized historical research would rely. As a result, he successfully established the Massachusetts Historical Society as the institution to assume the responsibility of collecting, preserving, and making accessible material for American historical research.²