Althorp Papers. Vol. md. Letters from his sister, Lady Sarah Spencer. For Spencer's letters to Sarah see Add. MSS 77720-77722 below; 1851, [1856?]-1910.
Althorp Papers. Vol. mdv. Letters from Margaret (nee Baring), wife of Charles Robert Spencer, and their children, including some by Albert Edward John (Jack), later 7th Earl Spencer; 1883, 1899-1910.
Althorp Papers. Vol. mdviii. Letters from: 1. His uncle, George Spencer, known as Father Ignatius, Superior of the Order of Passionists in London; 1858-1863. 2. His aunt Frances, Dowager Lady Clinton; 1851-1872, n.d.
Althorp Papers. Vol. mdix. Letters from: 1. His aunt, Isabella, Marchionness of Exeter; 1851-1874. 2. Brownlow Cecil, 2nd Marquess of Exeter and husband of Lady Isabella. Includes a copy of a reply from Spencer; 1851, 1860-1866.