Correspondence, manuscripts, diaries, journals, notebooks, legal and business papers, memorabilia, photos, and other papers, together with Gannett family papers. Includes correspondence of Gannett's grandfather and father, Unitarian clergymen Ezra Stiles Gannett of Boston and William Channing Gannett; 91 letters, 1796-1817, from Gannett's great-grandfather Caleb Gannett to John Mico Gannett, and journals of his grandmother Anna Tilden Gannett. Lewis Gannett's correspondence (including some carbon copies of outgoing letters) reflects his interests in current literature and in political activities such as the American Fund for Public Service. There are many letters from authors of volumes published in Doubleday's Mainstream of America Series, edited by Gannett. Manuscripts include juvenile compositions and early writings reflecting his initial desire to be a naturalist; essays and book reviews; Cream Hill, his book about country life; the Harper Book of Family Verse, which Gannett edited; and an incomplete autobiography.