- CollectionCamb. Medieval History - Papers relating to the Cambridge Medieval History Series
- SeriesBox 1-2 - Letters to and from contributing historians to Cambridge Medieval History
- SubseriesBox 2 - Letters relating to historians M-W
- File47 - Letters from C. H. McIlwain
- Item1 - Autograph letter, signed, to J. R. Tanner from C. H. McIlwain, Cambridge, Mass
- Item2 - Autograph letter, signed, to J. R. Tanner from C. H. McIlwain, London