When and by whom these private letters were gathered and bound up together remains unclear. The letters follow two chronological sequences: those received by Sir Frederick between 17 April 1865 and 12 June 1867, numbered 1-171; and copies of those he sent, 30 April 1865-28 May 1867, numbered 1-44 (with a duplicate 14). Each of these numbers applied to any enclosures with the letter. Dockets indicate that these letters had formed part of a different filing system during Sir Frederick's lifetime. These Private Letters to and from the Commander of the Forces, the governors of colonies in British North America and the West Indies, and British consuls in the United States focus on information-gathering, exchanges and assessment relative to the defence of those colonies; the threats posed by the Fenian Brotherhood and the prosecution of captured Fenians; traffic in surplus Civil War weaponry; American access to British North American fisheries; tariffs, trade and the Reciprocity Treaty. Letters exchanged with the American Secretary of State focus primarily on the Fenians. Dockets on some letters record transmission of selected information to and from the Foreign Office and the Colonial Office. The absence of postal markings on integral covers and references within letters point to the use of messengers to ensure confidentiality and speed of communications. Though letters refer to telegrams, no texts survive to demonstrate whether they were encrypted. Taken as a whole, the correspondence outlines practices in the employment of and payments to secret agents, the development of information networks, and the use of private channels outside the offical system of communication by despatches. A similar volume, bringing together copies and drafts of 108 Private Letters from Sir Frederick to the Foreign Secretary, 1865-1867, which sold at auction in 1973 and now resides in the University of Rochester Library (with a photocopy in the British Library, reference RP 950) demonstrates that a parallel exchange of Private Letters ran in tandem with the official imperial channel of Despatches between the British Legation at Washington and London (for which, see Foreign Office 5). Sir Frederick's copies and drafts may be compared with the texts which Lord Monck retained (see MG 27, I B 1).
