Correspondence, manuscripts of poems, and manuscripts of lectures by Benjamin. The correspondence consists of original letters of Benjamin, typescript and photostatic copies of Benjamin letters in other libraries, and letters to Benjamin from some of his literary contemporaries including Paul Hamilton Hayne, Willis Gaylord Clark, John Lothrop Motley, and Fitz-Greene Halleck. Many of the letters relate to Park Benjamin's lecture tours. There are other family letters and many documents relating to the Benjamin family,and two letterbooks of John Lothrop Motley. Also, a large amount of genealogical material of the Benjamin family, and its related families from the 16th century to the present day. There are also financial records, monographs, clippings, and photographs.

Correspondence between William Samuel Johnson, 1727-1819, and his son Robert Charles Johnson, 1766-1806, concerning personal business in Connecticut and a father's advice to a young man entering his law career. Some of the father's letters of special interest were written during his term as U.S. Senator (1791), and some concern British-French trade relations, 1793. There are also copies of letters to Johnson from Cadwallader Colden, Silas Deane, James Duane, John Fitch, Jonathan Trumbull, and William Williams. Other letters have been added