Papers of Chicago historian and librarian at the Chicago Historical Society and an early member of the Newberry Library staff. Included are letters, some of which are to or from editors of the Chicago Daily News and the Chicago Tribune regarding historical features of the papers. Also, many examples of McIlvaine’s drafts and writings on Chicago history, especially of buildings, streets and landmarks, a few pieces of memorabilia, and seven snapshots of 1920s Chicago.