Abstract Collection contains correspondence, videocassette, slides, articles from various publications, and several artifacts, related to the Chesapeake and Ohio Canal. The material covers the years 1950-75. This correspondence is between Mr. Durham had his friends and associates as they worked to protect and preserve the C & O Canal.

Abstract 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.