The Morton D. May Papers pertain to all aspects of Mr. May's collection of art. Correspondence files consist of letters, invoices, and receipts between Mr. May and artists, dealers, galleries, museums, and universities. The correspondence documents his purchases and exchanges of paintings, sculpture, prints, drawings, and objects in the following areas: art of the Americas; Oceanic art; African art; contemporary American art; German art, particularly the work of Max Beckmann. There are also papers concerning exhibitions to which May lent; requests for permission to publish reproductions; conservation of the May collection; and gifts to institutions.

Two files contain lists of works in the collection; many with valuations, loan numbers, and/or accession numbers.Photographic negatives and prints are of objects in the collection or objects offered by dealers to May.

Eighteen notebooks contain information on the collection in the form of accession records, including May's own accession sheets as well as copies of the St. Louis Art Museum's record sheets. Photographs and miscellaneous papers are included in several notebooks.