Finally made it to Fredericksburg and found the suggestions (esp. the terrific post from WellFedRed, below) to be very helpful, despite my lousy timing for good chow all weekend.
I arrived in late afternoon, hungry, when many places were closed between lunch and dinner. Sammy Ts revived me nicely with a substantial salad (the small size!) of baby spinach with falafel, tabouli, and tahini dressing. The falafel were not quite traditional with their creamier texture, but very tasty and satisfying. Sat outside, relaxed, watched people stroll up and down Caroline. Late in the evening I found myself peckish, with kitchens all closed. Bistro 309 saved us from grumpiness with an ad hoc plate of roasted garlic, cheese, and toast (and generosity) with our drinks, also providing good company and chatter. I sorely wish I could have made it to Jake & Mike's and 623. Next time I'm in Fredericksburg, whenever that is, I'll be well-armed with a restaurant agenda!