This collection consists of Hoover's personal papers, materials covering his various patents on airplane propeller parts, and the legal issues generated over those patents. In addition, there are materials related to his work as a farmer, and the owner of a transmission and pulley company.

Research collection of historic aviation publications. Primarily consists of black and white photographs of mid 20th century airplanes. Photographers Eric Lundahl, Alan H. Wiley, Peter Bryn, and Ted J. Koston are noted, and a stamp for the company, C.E. Galloway Pictures, is featured on many. The type of aircraft pictured is handwritten on the back of most photographs.