The Frank R. Diffenderffer Collection contains documents collected by Mr. Diffenderffer. These documents are primarily from the eighteenth and nineteenth centuries and include letters, legal and court papers, indentures, receipts, property and probate records, and financial and military papers. The people and businesses represented include George Ross, Jasper Yeates, A. Herr Smith, Timothy Matlack, Mount Hope Furnace, and the Lancaster, Elizabethtown & Middletown Turnpike Road Company.