Althorp Papers. Vols. mmdlxviii, mmdlxix. Letters to Beauchamp from his father Horace; 1827-1851, n.d. For Beauchamp's letters to his father see Add. MS 77844. Two volumes.
Althorp Papers. Vols. mmdlxxi, mmdlxxii. Letters to Beauchamp Seymour from Thomas George Baring, 1st Earl Northbrook, First Lord of the Admiralty, 1880-1885, relating to Beauchamp's duties as Commander in Chief in the Mediterranean; 1880-1883. Two volumes.
Althorp Papers. Vols. mmdlxxiv-mmdlxxix. General correspondence of Beauchamp Seymour, being mostly letters addressed to him. Many relate to naval matters; [circa 1827]-1894, n.d. Partly French and Italian. Six volumes.
Althorp Papers. Vol. mmdlxxxii. Two illustrated congratulations presented to Beauchamp 'in recognition of his distinguished services in the late war in Egypt'; one from the Worshipful Company of Cutlers of London, the other from the Lord Mayor, Aldermen and City of London presented jointly to Be...
Althorp Papers. Vol. mmdlxxxviii. Letters to Adelaide from her brother Beauchamp; 1834-1864. For Adelaide's letters to Beauchamp Seymour, see Add. MS 77870.
Althorp Papers. Vols. mmdlxxxix-mmdxci. Letters to Adelaide from her brother Charles; 1845-1854. For Adelaide's letters to Charles Seymour, see Add. MS 77853. Three volumes.
Althorp Papers. Vol. mmdxlii. 1. Horace Seymour's letters to Lord Henry Seymour; [circa 1810]-1813. 2. Letters to Horace from his first wife, Elizabeth Malet Palk; 1818-1821.