The John C. Evatt papers contain financial and administrative records from the Michigan Artificial Breeders Cooperative, Inc. (MABC). The collection includes records of sales made by the organization within Evatt's jurisdiction, summaries of receipts, membership applications, and member breeding records. Many of the documents in the collection contain names and address of the farms in the areas of Goodrich, Grand Blanc, Davisburg, Oakland County, Michigan. There is also correspondence to members, meeting minutes, the MABC Newsletter and Intercom, two photographs of the MABC board, and sire information.

In addition to MABC-related materials, the Evatt papers also contain a number of publications related to agriculture, dairying, and farm life as well as a manual of the Congregational Church of Grand Blanc, Michigan. There are also Evatt's school schedules, sports tickets, and correspondence from his time at MSC in the 1930s.