Francis Scott Key was buried in Frederick, MD about 45-60 minutes from Washington, DC. That makes it a perfect day or afternoon trip from the city.
It was humid and warm, but not awful as the end of summer can be sometimes. The tourist bureau in town has a pamphlet with a walking tour of the town. You walk along a creek, through the old streets, along a beautiful park. In particular, this park was founded for “fun and sane amusement”.
Frederick is also near the Antietam battlefields and was a hospital station during the civil war. The city is known for it’s cluster of spires and many churches and bell towers. Overall, a lovely afternoon!