Collection of mostly outgoing correspondence, manuscript and published writings, diaries, notebooks, notes for stories, clippings, photographs and some miscellaneous material relating to Mary Hartwell Catherwood's life and career.

With the exception of a few incoming letters, the correspondence in the collection is mainly letters Catherwood wrote to her aunt, Harriet H. DeVault, to a friend, Eleanor Ruthrauff, and (mostly in 1891) to her husband, James Steele Catherwood. Of the incoming correspondence, two letters are originals: one from Canadian writer, Sir John George Bourinot, and the other from actor Otis Skinner. The rest of the incoming correspondence consists of photocopies of a few letters from James Whitcomb Riley and Eugene Field.

Besides correspondence, there are three notebooks of jottings, ideas for writing and miscellaneous notes; a small diary kept on an ocean voyage in 1891; some recipes and loose memoranda; newspaper clippings; a biographical article and a published bibliography of her work; a copy of a Thomas Nast drawing; and photographs of Catherwood and Otis Skinner.

Half the collection is made up of examples of her work, both in manuscript form and from published sources.