Most of the details of Margaret Agnew Blennerhassett's life remain obscure. What is known of her is derived from information about the males in her life: that she was a "daughter of the Lieutenant Governor of the Isles of Man, and grand-daughter of General Agnew, killed in the battle of Germantown, a young lady of high family connexion, great beauty and accomplishments" (Montreal Gazette, 28 January 1841). She married Harman Blennerhassett sometime between 1796 and 1800 and either went with him to the United States or joined him there (accounts vary). Much has been written about her husband and his seemingly naive involvement in the "Aaron Burr affair" in 1806, as a result of which he lost his home and possessions, his estate on an island in the Ohio River, and a large portion of his considerable fortune. After living for some years on a plantation he then purchased in Mississippi, the Blennerhassetts...