The Gysbert van Steenwyk, Jr. series relates almost entirely to his many business interests, in the form of correspondence; education; business interests; financial records; and miscellaneous. Correspondence has been divided into business correspondence, dating from 1909-1958, and personal correspondence, from 1895-1925. Personal correspondence consists mainly of letters from his mother Mariette van Steenwyk and from his college friends. The education subseries consists exclusively of class notes taken during 1893-1897 when he was attending Yale University. The subseries titled business interests contains financial records of the La Crosse Boot and Shoe Manufacturing Co. (1899-1925), balance sheets of the La Crosse Rubber Mills (1905-1929), and miscellaneous reports from other local and national companies from the era. Van Steenwyk's financial records include bank account records and a ledger from 1902-1905, income tax records (1915-1929), property tax records (1905-1930), and a record of his employees' wages and social security tax withheld from 1951-1962.