"The C & O Canal … 1959."; "Douglass, William O. "; "Chesapeake and Ohio Canal (Md. and Washington, D. C.)"; "Douglass, William O. "; "undated"; "Journal article reprint from: The Living Wilderness."; ""; "P5802"; "pec"; "Chesapeake and Ohio Canal (Md. and Washington, D. C.)"; "14256"; .