This series contains three categories of material: legal papers, financial reports, and bills for the living expenses of Mary Virginia McCormick and members of her household.

Among the legal papers, documents of particular importance are those giving control of Mary Virginia's share in the McCormick estate to Cyrus McCormick, Jr., in 1884, and those declaring Mary Virginia insane and establishing a trust to manage her affairs, in 1889-1890.

The financial reports fall mainly between the years 1900 and 1911, and consist of reports made by the head of Mary Virginia's household to the conservators. In addition, there are reports submitted by the trustees (originally composed of Nettie Fowler McCormick, Cyrus McCormick, Jr. and Eldridge M. Fowler) and conservators to the state courts. The trustees' reports concern the investment of Mary Virginia's fortune, while the conservators report on the expenses of Mary Virginia and her household.

The third category, bills, begins in 1879, before a trust was set up. The bulk of the material deals with the period after 1888, when Mary Virginia was being treated for mental illness.

The volumes in this series contain additional financial records. The first volume is an account of grocery expenses in 1882, while Mary Virginia lived in New York. The second volume is an expense book kept by Dr. O.E. Davis when Mary Virginia was taken on a trip to Europe. The remaining notebook volumes cover daily expenditures and were kept by Mrs. L.J. Moses while she was head of the household in 1893-1896. Finally, there are nine volumes of check stubs.