If you are planning on attending the Presidential Inauguration this January 21st and are using public transportation, Metro will be providing an express bus schedule in addition to the weekday schedule from the campground to College Park Metro Station and back.
The supplemental 83X bus schedule, which will take you directly to and from the Metro, is as follows. (Please note this does not include the regular weekday bus schedule):
DEPARTING FROM CHERRYHILL CAMP GROUND
DEPARTING FROM COLLEGE PARK STATION
Here is a link to the Metro website which will provide you with further details if you have any questions regarding schedules.