Sounds like taxi or car service is the way to go. If we are doing lots of walking we might have to bring our strollers. I had thought that taking the train could be part of the adventure (my boys love trains) but worried about being able to get a taxi from union station to our hotel on the 4th.
good to know about hotel rooftops. I will look into that. That solves a lot of the usual problems when we are out with the kids. there'll be food and bathrooms available at hotels. Thanks!
Question: if everyone is at the mall how is traffic particularly on the roads from BWI-DC on the 4th in the afternoon? our flight arrives around 3 pm.

Also, does anyone have a car service to recommend? It looks like super shuttle has private cars according to their website.