Includes hundreds of correspondents, of whom only a few of the better known are mentioned. Relates principally to Matson's effort to locate official records and manuscript material about the Nandi and neighbouring groups with government officials serving in various districts, officials who served in Nandi previously, missionaries, settlers, and representatives of various libraries and archives. Subjects also include Matson's efforts to secure official support for his research....

Correspondents include: D. Anderson C. Brantley T.H.R. Cashmore A. Clayton R. Dunstan L. Farrant C. Hobley.

Correspondents include: J. Lonsdale E. Bradley Martin T. Ofcansky E. Rodwell J. Rowe E. Trzebinski R. Waller.

Subjects include most areas of Matson's interest in East African history, Matson's writings, Dictionary of East African Biography, and documentation for East Africa. See also Matson's correspondence with Thomas in the H.B. Thomas Papers at the Royal Commonwealth Society.

Includes correspondence about Thomas's estate after his death in 1971.

Subjects include numerous aspects of East African history, largely late 19th century, particularly the Uganda Railway, Railway boats, Uganda Road, and Frank Hall.