There's No Minimum RoadTrip
Thanks for the reminder that RoadTrips don't have to be grand multi-thousand-mile treks to be an adventure. I've also had the pleasure of driving through the area you explored and there are still many other little gems in that general vicinity to fill another day or more, including fort Frederick, the Chesapeake and Ohio Canal, the Great Falls of the Potomac, Catoctin Mountain National Park, the town of Emmitsburg and many others. I'm glad you enjoyed your day trip.
AZBuck
My favorite is still the "20 Hour RoadTrip"
You might enjoy my article about the joys and freedoms to be achieved by engaging in a 20-hour road trip.
Also, we are establishing a list of Day trips from hub cities in the United States, eventually we hope to have 200+ of these. But here are few dozen of the ones we've identified thus far.
Mark