The collection consists of the papers of George Peabody Wetmore (1846-1921), governor of Rhode Island, 1885-1887, U.S. Senator, 1895-1913, and other papers collected by him. These papers, going back to the 17th century, reflect Wetmore's interest in New England history. Special emphasis is given to Rhode Island (especially Newport) and Massachusetts (especially Boston and Salem), and to the family names Dudley and Derby (to whom Wetmore was related through his mother), Wetmore, and Keteltas (to whom Wetmore was related through his wife). Some papers related to the Aaron Burr family have been transferred to the Burr Family Papers. The collection also contains some papers of General William Shepard (1737-1817; his daughter Nancy was Wetmore's paternal grandmother), who commanded the force which quelled Shays' Rebellion in 1787. (See the genealogical tables for the Wetmores and also for the Graftons, whose business correspondence forms a separate unit at the end of the collection.)
Wetmore's personal papers contain letters from many important Washington figures including Presidents Roosevelt and Taft. Among the most heavily represented of these correspondents are Elihu Root and John Hay. The letters are individually catalogued in the department manuscript catalog on microfiche.