Collection contains correspondence, obituaries, reports, photographs, slides, newsletters, booklets, membership data, programs, brochures, minutes, and by-laws. The material dates from the early 1800s to 2021 with the bulk of the material falling between 1954-2013. This material relates to the history of both the Chesapeake and Ohio Canal and the Chesapeake & Ohio Canal Association.

This collection contains newspaper clippings, newsletters, photographs, maps, guide books, certificates, color slides, reports, pins, membership cards, and other memorabilia. The material dates from 1927-1997, but the bulk of the material dates from 1951-1974. The material was collected by Orville Wright Crowder and relates to his tour and preservation work on the Chesapeake and Ohio Canal. Much of the materials consist of maps of Maryland, Pennsylvania, Virginia and Ohio.

Collection includes correspondence, brochures, pamphlets, newsletters, newspaper clippings, photographs, slides, scrapbooks, audio and video tapes, and cloth materials. The material dates from 1943-2011. The material in the collection covers the history of the Potomac Area Council of American Youth Hostels, especially the activities of its former Executive Director and board president, Don Messersmith.

Collection contains materials related to Thomas Hahn's involvement in the C&O Canal Association, as well as other canals related to the C&O, and canals in general. A large part of the collection consists of photographic negatives, slides and prints of the C&O Canal. Most of these photographs, negatives, and slides relate to illustrations in publications that he authored or co-authored. Other items include reference material for his books, correspondence, and maps.