The Mary Hays manuscript material in the Pforzheimer Collection consists of letters to the philosopher and novelist William Godwin, letters to the writer and translator William Tooke, and a bound volume containing a manuscript copy of 102 letters between Hays and John Eccles. Also held is Hays's copy of Wollstonecraft's Vindication of the Rights of Woman (1792); many pages contain light penciled annotations, some of which may be in the hand of Hays. All items are published in The Correspondence (1779-1843) of Mary Hays, British Novelist, edited by Marilyn L. Brooks (Edwin Mellen Press, 2004).