University College London Special Collections also holds notes by De Morgan for an introductory lecture at University College London, 1862 (Ref: MS ADD 2); a manuscript of De Morgan's introductory lecture at the opening of classes in mathematics at University College London, 1828, with notes for another lecture (Ref: MS ADD 3); a student's notes on lectures given by De Morgan at University College London, 1847 (Ref: MS ADD 5); papers relating to the history of the De Morgan family (Ref: MS ADD 7); 'Elements of statics', 1827, a volume written for the Society for the Diffusion of Useful Knowledge but never published, used by De Morgan as evidence of his work when applying for the Mathematics Chair at University College London (Ref: MS ADD 27); mathematical fragments, letters, and papers of De Morgan, c1863-c1871 (Ref: MS ADD 69); correspondence between De Morgan and George Boole and others, 1842-1881 (MS ADD 97); letters of thanks from De Morgan to F Hendriks for publications, 1852-1866 (Ref: MS ADD 147); two items of correspondence between De Morgan and Sophia Frend, 1836 and undated, a letter from De Morgan to Sir Jonathan Pollock, 1865, and miscellaneous undated verses (Ref: MS ADD 163); over 100 letters from De Morgan to the Society for the Diffusion of Useful Knowledge, 1827-1844 (Ref: SDUK); over 70 letters to Henry Peter Brougham, 1st Baron Brougham and Vaux, 1842-1866 (Ref: BROUGHAM); letters relating to University College London business, 1828-1866 (Ref: COLLEGE CORRESPONDENCE); two letters to Henry Clark Barlow, 1857 (Ref: BARLOW); a letter to Sir John Bowring, 1839 (Ref: MS OGDEN 62/2/39); a letter to Richard Francis Weymouth, 1849 (Ref: MS ADD 231/31); two letters to an unknown man, 1857, 1860 (Ref: MS MISC 3D); papers of the London Mathematical Society, in which De Morgan was involved (Ref: LMS); a letter to Thomas John Hussey, 1847, and one to Sir William Rowan Hamilton, 1857 (Ref: MS GRAVES 23); c2,860 anagrams on the name Augustus De Morgan by John Thomas Graves (Ref: MS GRAVES 36); letters from James Smith to the editor of the 'Athenaeum', William Hepworth Dixon, arguing against De Morgan on the quadrature of the circle (Ref: MS ADD 118); various annotations, inscriptions and inserts made by De Morgan in printed works, including letters addressed to him, some from eminent contemporaries (see card index at University College London Special Collections for details).
The University of London Library holds correspondence and papers of De Morgan (Ref: MSS 36, 165, 238-41, 321-2, 775-6, 786) and his family (Ref: MS 913). The British Library, Manuscript Collections, holds correspondence with Charles Babbage, 1830-1850 (Ref: Add MSS 37185-200 passim). The Royal Society, London, holds c384 items of correspondence with Sir John Herschel, 1831-1870 (Ref: HS), and 26 letters to Sir John Lubbock, 1832-1860 (Ref: LUB). The Royal Astronomical Society Library, London, holds correspondence and papers, 1831-1866 (Ref: MSS de Morgan), and letters from De Morgan to the Society, 1831-1866 (Ref: RAS letters). Oxford University, Bodleian Library, Special Collections and Western Manuscripts, holds family correspondence and correspondence with Lady Byron (Ref: Dep Lovelace Byron) and miscellaneous correspondence (Ref: MS Autogr d 14). Cambridge University Library, Department of Manuscripts and University Archives, holds 205 items of correspondence with Sir George Airy, 1850-1870 (Ref: RGO MSS 942-52); 37 letters to William Hepworth Dixon, 1856-1857 (Ref: Add 9428); ten letters to Lord Kelvin, 1845-1849 (Ref: Add 7342, 7656). Cambridge University, Trinity College Library, holds 69 letters to William Whewell, c1832-1866 (Ref: Whewell MSS). The National Library of Scotland, Manuscript Division, holds 19 letters to Alexander Campbell Fraser, 1855-1864 (Ref: Dep 208). Edinburgh University Library holds 12 letters to James Halliwell-Phillipps, 1845-1851 (Ref: LOA). The Royal Observatory Library, Edinburgh, holds a catalogue of mathematical books (Ref: NRA(S) 2657). Trinity College Dublin holds 252 letters to Sir William Hamilton, 1841-1865 (Ref: MS 1492). The American Philosophical Society Library, Pennsylvania, USA, holds c30 letters, 1841-1866.