The sub-series documents the creation of histories of the Montreal YMCA. It holds research notes, manuscripts, correspondence, and other documents related to Harold C. Cross' book One Hundred years of Service with Youth: The Story of the Montreal Y.M.C.A. 1851-1951, published by the YMCA in 1951.
The sub-series includes timelines and historical sketches, research notes, correspondence, essays, press clippings, books, photographs, and other materials.