The Nils Andreas Olsen Collection consists of journals, ledgers, and other account books of the Evans Hardware Company, Princeton, Minnesota, covering functions prior to 1920; records of Alfred Erickson, Washington County, Minnesota; minutes, payroll book, cash books, and other records of the Golden Valley Creamery Association and its member groups, a cooperative functioning from 1908 to 1910; some 19th century military post records; and other miscellaneous material.