Subjects: Correspondance (sorted alphabetically by title)
- Marion, Francis, 1732-1795 -- Correspondence
- Marx, Karl, 1818-1883 -- Correspondence
- Medical personnel -- United States -- Correspondence
- Mendelssohn-Bartholdy, Felix, 1809-1847 -- Correspondence
- Mendes, Carlos Fradique -- Correspondence
- Mérimée, Prosper, 1803-1870 -- Correspondence
- Michelangelo Buonarroti, 1475-1564. Correspondence
- Mikes, Kelemen, 1690-1761 -- Correspondence
- Missionaries -- India -- Jammu and Kashmir -- Correspondence
- Montagu, Mary Wortley, Lady 1689-1762 -- Correspondence
- Montagu, Mrs. (Elizabeth), 1718-1800 -- Correspondence
- Mothers -- Correspondence
- Moukhanoff, Helen de Smirnoff, 1878-1963 -- Correspondence
- Mozart, Wolfgang Amadeus, 1756-1791 -- Correspondence
- Musicians -- Correspondence
- Napoleon I, Emperor of the French, 1769-1821 -- Correspondence
- Naturalists -- Correspondence
- Naturalists -- Great Britain -- Correspondence
- Naturalists -- United States -- Correspondence
- Nelson, Horatio Nelson, Viscount, 1758-1805 -- Correspondence
- Nobility -- Great Britain -- Correspondence
- Novelists, American -- 19th century -- Correspondence
- Novelists, English -- 18th century -- Correspondence
- Novelists, English -- 19th century -- Correspondence
- Novelists, French -- 19th century -- Correspondence