I haven’t been on the Mall since last March (March ’04), so my information is about six months stale. I strongly recommend that you check out the National Parks Service excellent Web Page for more details, http://www.nps.gov/nama/
Lincoln Memorial: is still as accessible as ever for peds, very little security hassles. A wonderful place. Make sure to read Lincoln’s Second Inaugural Address inscribed on the inside of the monument (on the North Wall—the side facing the State Department/Foggy Bottom). One of Lincoln’s best works, and a remarkable “apology” for the sin of Slavery.
Washington Monument: Is still fairly accessible. It is ringed by a heinously ugly wall of low concrete barriers, and a higher wall of concrete fencing on the street sides. But you can still walk up to it easily and take pictures. Getting into the monument itself now requires an advance (Free) ticket as well as a security screen. Tickets are only 9-5, so if you are there PM
, no luck I guess. But check out the National Parks’ Service Web Page, above, for more details.
Capitol: This is real tragedy, you used to be able to walk right up the steps, now it is all fenced off. They are also in the process of building a new visitors center which adds a rather large amount of unsightly construction mess—on the East side of the Capitol. But you can still get fairly close to get detailed pictures. If you want to visit inside the Capitol you need to get a ticket at the tourist booths on the edge of the West Grounds of the Capitol, close the U.S. Botanical Garden. While you are at the Capitol take a short walk, Northeast, over to Union Station, that is also worth a look.
White House: Has never been very accessible (at least in my lifetime), but you can get closer than you would think. The only real visible side is the south side across from Lafayette Park, where you can take a pictures through the Fence.
Also, don’t forget the Vietnam Memorial (“the Wall”) and the Korean War Memorial, which are both close to the Lincoln Monument. AA777 also mentions the World War II
Monument, this is half way between the Lincoln Monument and the Washington Monument (and in my opinion, a real eye sore); AA777 also mentions the Museum of the American Indian; I’ve not seen this in its completed state, but apparently it is very stunning now. It is close to the Capitol (relatively) on Independence Ave.
You didn’t ask about the Museums on the Mall (most of which are part of the Smithsonian) so I won’t go into that, but please do be aware that there are generally lengthy lines getting into these museums (for security purposes, they are all free admission) with the exception of the National Gallery which is blessed with three separate entrances, and so no long security lines. If you are interested in architecture, the best one is the Museum of Natural History (with its amazing beaux-arts foyer).
Parking in Washington is extremely limited and a hassle during the week (and I say that as someone who routinely parks on the streets of Manhattan). Is it possible you can park at one of the Metro stops and take the Metro in? Otherwise be prepared to pay $10-$20 for garage parking. The Metro is quicker too generally. Get off at M-Smithsonian and do a circle around the Mall bringing you back to M-Smithsonian. The Distance from the Lincoln Memorial to the Capitol is a little over two miles.
Washington, D.C. is a great town. Too bad you only have enough time for a quick trip.