This series contains materials relating to William L. Honnold's career after his return to the United States in 1917. The bulk of the materials date from 1922, when Honnold moved from New York City to Ocean Park, California, through 1930, when Honnold's (California) secretary, Neil C. Cross, instituted a new chronological filing system (Series 3: Chronological files). The records prior to 1924, when Honnold engaged Cross as his secretary, are incomplete, and consist primarily of (1) a few papers relating to Honnold's service as director of the New York office of the Commission for Relief in Belgium, (2) telegrams and correspondence relating to Honnold's 1918-1919 mission to Europe on behalf of Guaranty Trust Company and other United States financial institutions to help restart the Belgian economy, and (3) records of a small number of mining and investment ventures. The series contains some materials, in particular legal, and tax documents in Subseries 3.5: Financial and legal, dating from 1931 through 1938. These files were originally maintained by Cross among the files for the appropriate years in Series 4: Chronological files, but were removed, probably in the 1980s by a prior processor of the collection, to a separate box. As these files had been refoldered and the folder titles altered, it was impossible to determine with absolute certainty to which year each of these files belonged; consequently, no attempt was made to reincorporate these files into Series 4, and they were retained where they were found. In addition, files relating to the Anglo American Corporation of South Africa, the Honnold Foundation, and personal or family matters were transferred to Series 5, 6, and 8, respectively. The remaining materials have been arranged by the current processor into five subseries: (1) Business and investments, (2) Civil and philanthropic activities, (3) Correspondence, (4) Financial and legal, and (5) Memberships. Files within each subseries are ordered alphabetically. The most efficient method of access to the files is the card index Cross compiled (Boxes 107 and 108), which indicates the title of the file in which correspondence on a particular subject or with a particular individual can be found.