The collection consists of the personal papers of Morris, which reflect his interest in the world of letters, art, business, and government, as well as the social world of Philadelphia. The collection includes his original manuscripts for novels ( Hannah Bye and The Landlord's Daughter), poetry ( A Duet in Lyrics, Lyrics and Landscapes, and Madonna and Other Poems), short stories ( Tales from Shakespeare and Tales from Ten Poets), essays ( Papers to Put in Your Pipe), non-fiction ( Confessions in Art), biographies ( Walt Whitman and William T. Richards), and book reviews which appeared in periodicals such as Scribner's Magazine, Ladies' Home Journal, and the Century Magazine. Also included are the original manuscripts for "Books of the Month" published in Lippincott's Magazine.

Much of the collection is related to the American art world of the late nineteenth and early twentieth centuries, including correspondence from such artists as John La Farge, Joseph Pennell, J. Alden Weir, William M. Chase, Cecilia Beaux, Childe Hassam, Violet Oakley, J. McClure Hamilton, Elihu Vedder, and the sculptor Augustus S. Gaudens, to name but a few. Also, there are papers from institutions of art such as the Pennsylvania Academy of the Fine Arts, the Corcoran Gallery, the Art Association of Newport (R.I.), the Albright Art Gallery, the Buffalo Fine Arts Museum, the Boston Museum of Fine Arts, the St. Louis Art Museum, and the National Academy of Design. In addition, the records of the Rome International Art Exposition of 1911, of which Morris was commissioner-general, are included. Additional papers contain family correspondence dating back to the 1860s, as well as a number of daguerreotypes of family members.

Morris's papers reflect his interest in government at all levels, local, state, and national. Also included are the papers of Philadelphia societies and clubs such as the American Philosophical Society, the Browning Society, the Franklin Inn Club, and the Triplets. Morris was related by marriage to the Wharton and Lippincott families of Philadelphia, and his papers contain correspondence with many of the first families of the city. The Keats-Shelley Memorial Committee and the Hall of Fame are also represented. And there is lengthy correspondence between Morris and Robert Underwood Johnson who shared many literary interests, as well as material relating to Walt Whitman whose life and works were for Morris a life-long passion.