This subseries contains correspondence files for William L. Honnold for the period 1919-1930. Approximately half the correspondence relates to fellow mining engineers in the United States, South Africa, and Great Britain. Honnold maintained correspondence with several of these individuals, including Samuel Evans, Fred Hellman, Charles W. Moore, and Thomas Arthur Rickard, for decades. Seeley G. and Harvey S. Mudd, Lewis Webster Wickes, and Philip Wiseman shared offices with Honnold and partnered him in various business ventures over a period of many years. Of those correspondents who were not intimately connected with mining, a significant number, including Sir Charles Briggs, Sir Charles Crewe, Sir Percy Fitzpatrick, T. W. M. Fuge, and Sir Harry Ross Skinner, were from government and military circles in South Africa. Edgar Rickard (Thomas Arthur Rickard’s cousin), with whom Honnold maintained a business relationship for decades, was a friend and colleague from the Commission for Relief in Belgium. The subseries contains considerable correspondence with Caroline Honnold’s nephew, Rollin Beach Burton (1881-1973), who from 1917 to 1937 served as Honnold’s secretary and personal assistant (“fiscal agent and income tax adviser”) in New York; this correspondence relates to all aspects of Honnold’s life, personal as well as business. There are also substantial General Correspondence files, for correspondence that neither Burton nor Neil Cross (1886-1964), from 1924 Honnold’s secretary in Los Angeles, felt warranted a separate folder. Access to the Burton and General Correspondence folders is greatly assisted by the alphabetical card index for 1924-1930. The “Christmas greetings and gratuities “ file, continued in Series 4: Chronological files, contains the names and addresses of those friends and colleagues to whom Honnold felt close enough to send communications at Christmas.