I spent 12 days in DC last July. It was phenomenal, save for the weather that was so bad on 4th of July that they had to use footage from past years on the nationwide broadcast of a Capitol Fourth. Whoops. Keep in mind that I'm a history major with a focus in American History. Washington, DC is my all-time favourite destination - with Boston as a close second.
1. Go to the Smithsonian Museum of the American Indian when you are hungry on the Mall. It's the best food, by far, you will have anywhere on the Mall, in my humble opinion. The food trucks are a close second. I've eaten at the National Art Gallery, most of the museums, and several dodgy hot dog carts/street vendors. The Museum of the American Indian has a food court organized by regional tribal cuisine, and it's beautifully prepared. VERY good. All the other museums have the exact same boring fare as any other.
2. Schedule your tours now. All of the ones you think you might want, and do it through your congressional representative so you get the better tours. The White House tours come in about three weeks before your trip, so don't be spooked by that.
3. There's a Circulator bus that does the Mall, and it's a dollar each trip. Load a Smart Trip card at Union station or another of the Metro Stations and you can use that for your fares. Very easy. If you're going to ride the Metro, get the week pass and don't worry about it, but check the fine print to make sure it covers the Circulator.
4. I stayed at the Marriott Marquis, which is the hotel connected to the Convention Center and is within easy walking distance to a Metro station with a short trip to the Mall. Do it. The JW Marriott was very nice when I wasn't on my own budget, but I would never have stayed there on my own budget.
5. (Admins, this may be verboten but I'm not sure) I scheduled a class with the REI Outdoor School to paddle in a kayak on a sunset tour of the monuments down the Potomac. SO COOL!!!! I would do it again in a heartbeat. There's some good storytelling there, and you kayak from the little park at the end of the Reagan runway down to the Kennedy Center, eat dinner at the monument to the merchant marine, and then paddle back. It's amazing!!! You also get to see the side of the Pentagon, and they do a little talking about 9/11 as part of it.
6. Fly into Reagan. Way better than Dulles. But make time to go out to the Udvar-Hazy Center because the display of aircraft out there is ridiculously impressive. I was awestruck standing in the room with the space shuttle in front of me and the Enola Gay (dropped the H-Bomb on Hiroshima) in the other room.
7. Sweet Georgia Browns is off of Lafayette Square, and DELICIOUS food. Try to find time to go to Old Ebbits while you're at it, because you can just imagine the presidential hands that have been on those railings over the hundreds of years... Many deals were done there. And if you're over on the really sketchy area near the Convention Center, check out Busboys and Poets. It's a "third place" that has got to be VERY interesting right now given the current political climate there - and it's dedicated to Langston Hughes.
8. I loved the National Archives Charters of Freedom exhibition. It was this incredibly reverent experience of gazing upon the very documents of revolution, freedom, and resilience that founded our country. People risked their lives in signing them, and that fact is not lost in the room. The power of that exhibit is unbelievable.
9. The other places I loved, in no particular order are: The National Cathedral - WHOA! SO MANY side chapels and an incredibly beautiful place; The National Zoo - Quick trip to see the Pandas, along with the Cathedral; Free Concerts at Kennedy Center, every night at 6pm, and always a good show; The FDR Memorial and the MLK Memorial - Seldom traveled, and as the newer memorials on the Mall, quite thought-provoking; The Star Spangled Banner at the Museum of American History;
10. If you want to go to the top of the Washington Monument, the tickets are first come, first serve, and the line starts early. VERY early.
And get a National Parks Passport before you go - there are LOTS of stamps to be had for it!! If you're taking the kids, they'll love it. I walked my stinkin' feet off while I was there, and was all by myself so I had nobody to answer to but myself, and it was awesome.