Handwritten and typewritten drafts of manuscripts, reprints, bound volumes, printers' proofs, publishers' prospecti, correspondence, research notes, photographs, drawings, plans, and reports relating to Williams' teaching and research in physics, as well as a small amount of personal papers documenting his private life. His extensive correspondents are listed in the appendix, and included Arthur Stanley Pease and Stanley King (Presidents of Amherst College), Walter Crabtree Jr., Ray T. Bayless (American Society for Metals), M.F. Behar (Ed., Instruments), and David Landau (Nitralloy Corporation and Société des Amis d'Andre-Marie Ampere).

This collection is organized into six series:

• 1. PUBLISHED WRITINGS, 1904-1956
• 2. UNPUBLISHED WRITINGS, 1942-1954
• 3. GENERAL CORRESPONDENCE, 1915-1955, n.d.
• 4. HOUSE-BUILDING RECORDS, LINCON AVENUE, AMHERST
• 5. SIGNAL CORPS RECORDS, SCIENCE AND RESEARCH DIVISION
• 6. MISCELLANEOUS MATERIALS