Correspondence constitutes by far the largest series in the archive and it comprises mainly letters and notes to Mary Hamilton, but there are also some of Hamilton's own copy and draft letters and letters written to her husband, John Dickenson. Members of Hamilton's family and her large circle of friends and acquaintances are represented within the correspondence, including many significant figures of the period. The correspondence contains letters from Queen Charlotte and other members of the Royal family, Sir William Hamilton, Lady Charlotte Finch, Lady Mansfield and Richard Glover. Also included is correspondence from prominent members of the bluestocking circle such as Elizabeth Montagu, Frances Burney, Frances Evelyn Boscawen, Elizabeth Vesey and Mary Delany, as well as Court figures such as the Duchess of Portland and Charlotte Gunning.
The correspondence represents a significant resource for the study of the history of eighteenth-century Britain. The letters are full of details on a wide range of subjects, from the gossip and scandal of the day to affairs of state and the illness and recovery of George III. They discuss family news, Court life, marriage, fashion, literature, education, politics, servants, war, art and music amongst other subjects. The correspondence provides important insights into many aspects of the life of a socially 'elite' and educated woman in the late eighteenth and early nineteenth centuries.
The correspondence from members of the Royal family reveals the high regard in which Hamilton was held by them. As well as letters from Queen Charlotte, there are numerous letters from the princesses, who write of their affection for Hamilton. The Prince of Wales's letters to Hamilton have been removed from the archive and now reside elsewhere. Nevertheless, there are references to the Prince, and descriptions of Court balls Hamilton attended, including an account of a ball held for the Prince of Wales's birthday. Letters from Lady Charlotte Finch relate to the Royal household, instructions to Hamilton regarding her duties as sub-governess, and the deaths of two of the young princes. The archive also contains a draft copy of Hamilton's resignation from Court.
Elsewhere in the archive, the correspondence relates to women's education and Hamilton's intention to learn Latin. Both her guardian, William Napier, 7th Lord Napier, and Hamilton's future mother-in-law, Sarah Dickenson, advise against it. Napier writes that he will keep secret her learning and he notes that 'a Lady's being learned is most commonly looked upon as a great fault even by the learned' (HAM/1/19/18).
Other letters relate to the relationship between Sir William Hamilton and Lady Emma Hamilton. Lady Frances Harper, Hamilton's cousin, writes of her attempts to distance herself from Lady Hamilton and gives an unflattering account of her, commenting that she expected Emma to have 'much elegance of figure & manner. She has neither' (HAM/1/16/72).
The correspondence also details Hamilton's many social engagements at Bas Bleu parties, concerts, theatre performances and balls. She and her correspondents discuss literature including the works of friends such as Frances Burney, Hannah More and Richard Glover. Elizabeth Carter writes to Hamilton on Fielding's Tom Jones, advising Hamilton 'do not go staring & marry a Tom Jones blessing your stars all the while & thinking you have made a notable choice' (HAM/1/22/14). The correspondence relating to Hamilton's family includes details of Hamilton's engagement and marriage, the abandonment of Hamilton's cousin, Jane Holman, by her actor husband, Joseph Holman, and also various financial affairs, family disputes and the death of family members. The letters from Sir William Hamilton detail the negotiations with the Duchess of Portland over her purchase of works of art from him and he also writes on the 'delicate' issue of his mistress and later second wife, Emma Lyon.
The archive also contains sixty letters from Hamilton's husband, John Dickenson: he wrote to her throughout her marriage whenever they were apart.
Mary Hamilton is referred to throughout the catalogue by her maiden name.