If you have never biked the C&O Canal you have to check this out:
A 30-minute travelogue/documentary about the Chesapeake and Ohio Canal National Historical Park from a cyclists’ point of view. Explore the C&O and its unique and sometimes quirky places and the friendly faces you might meet along this 184.5 mile-long towpath.
https://video.google.com/videoplay?docid=-3225692865212695699&q=youcubed
More info on the C&O and how to plan your trip:
https://www.bikewashington.org/canal/index.php
oldId.20060725131249863
Biking in Baltimore