Will be spending an overnight in historic Annapolis at the end of march. Would like to hear any suggestions for fun stuff to do and see.

The tour of the US Naval Academy is great; so is just wandering around the waterfront area.

Second the previous poster! We had a good meal right on the water but I don't remember the name of the restaurant. Also enjoyed shopping up from the harbor.

Try McGarvey's for lunch. Look for Walter Cronkite; a sailor, he dines there often (has an entree named after him). Try Riordan's for dinner; informal dining downstairs, a small, finer dining room with upscale menu upstairs.
By all means tour the Naval Academy,its Bancroft Hall(the world's largest dormitory with a dining room seating 4,000), the chapel and crypt of John Paul Jones and the Academy museum with its huge collection of ship models (donated by an Army colonel).

Bob, in the event that you may be interested in Maryland blue crabs, there's a restaurant "off the beaten path" that we just loved. Cantler's Riverside Inn in Annapolis. It's an "extremely" casual pub-style restaurant offering seafood fare and platters of yummy crabs (if that's your thing). Locals may disagree, but I think it's better than the one closer to the Naval Academy.