Just to mention Mt. Vernon (Geo. Washington home) again.

Very informative tour...I think good for all ages.

Admission charges. Privately operated.

Easy access via metro and bus.
Metro Yellow line to Huntington. From Hunnintgon Sta. catch bus #101 (Fairfax Connector) or #151,#152.

On your way get transfer at departure metro sta. for transfer to bus. (save 65 cents per fare). Bus fare $1.00 (.35 with transfer)

This was one of my more enjoyable attractions.

Also, again, mention the Postal Museum across the street from Union Station.
Very "kid" friendly. Not crowded, interesting historical data about how postal service started and progressed.

Lovelee:

You have children that are the ideal age for D.C.! Wear extremely comfortable walking shoes.

Second the first place you must go is Smithsonian American History and Air & Space, both are far away from each other and there is a Blue Line subway stop from Smithsonian to Capitol to make the commute a piece of cake. Third place you must go to is Mount Vernon Virginia - home of George Washington. It is an amazing place with a tour of the mansion and a little museum with family artifacts at the side and an absolutely gorgeous view of the Potomac which you can view from all the chairs lined up outside on the back porch of the place. You can walk to all the little places that housed the kitchen (off the side from the house) and the laundry building and where the coaches were stored.

I'm going to disagree just a little bit with Stephanie on using the Blue Line and the Smithsonian museums.

A lot of visitors think that the Smithsonian Metro stop is THE stop for all the museums. As the museums are SOOO spread out, it is NOT always the best stop. Yes, it's great for "the Castle", Arts & Industries, Sackler. But for Air & Space or Native American Indian Museum, you would want to use Federal Center SW (make a left at top of excalator & proceed 2 blocks) Also all the mall area metro's are served by the Blue AND the Orange lines.

I've just returned from a 4 day trip to DC and used the new "Circulator Bus" (www.dccirculator.com) which runs between Union Station and Georgetown, with another route between Convention Center & SE Waterfront. $1 for all day. There is a stop close to your hotel (Residence Inn White House?). I'm at work now, will write more later.

Yikes, I thought the Circulator was $1 per RIDE! Does that $1 get you a pass of some sort?

The kiosks print out a receipt with a "paid thru 11:59PM on mm/dd/yyyy" type of "parking receipt". The kiosks are a dark green with a solar panel atop of them for power; the very same devices used along the streets in Georgetown to collect parking fees. In fact my receipt's preprinted info reads
"Parking Time Limit"
"Date Time"
"Price Parkeon"
"Display Ticket inside vehicle windscreen"

I thought it was "per ride" too, but signs inside the bus said to keep your receipt for rides the rest of the day. Temporary deal mayhe??

All of the above are great suggestions. I don't think that it is really necessary to take a day and an evening tourmobile tour. You see the same places. For the cost, the hop on, hop off option is rather useless. The Metro is a great means of transportation. I suggest taking the night tour. It is beautiful and they roll up the streets after 5.

I have seen mention of the gargoyles at the National Cathedral. Go to their website. They offer tours and tea on select days during the week. You have to book in advance but well worth it. We took the stained glass tour with tea afterwards. It was very relaxing after two days of muesums and it takes about 2 -3 hours.

Another tip is to buy tickets to the Washington Monument in advance. They are $2 per person online but you don't have to wait in the "free ticket" line. Well worth your time and patience.

Mount Vernon is wonderful and can be combined with a visit to Old Town Alexandria. Later in the spring plan to visit Mount Vernon in the late morning or later afternoon to avoid the crowds, but check the closing time -- you want to have a couple of hours to walk around and enjoy the grounds and view. The Mount Vernon Inn is better than the on-site food court and frankly about the same price for lunch.

We try to avoid the Smithsonian metro stop and use alternatives when possible. If you must use that one make sure you've got your tickets -- it is always crowded and the ticket machines have longer lines than other stations. L'enfant Plaza is another good stop for Air and Space and the Native American Museum.

We also love the cathedral, it is so peaceful after the mall. Lunch at 2 Amys, almost across Wisconsin from the Cathedral, makes a great morning.

Check out the Botanical Garden, it is right on the mall, between the Native American Museum and the Capitol. It is a hidden DC gem. They do excellent exhibits.

Hi lovelee...we too are going to DC over spring break. Ours is the week of April 10th, 06. We have booked a room at the Hampton Inn Crystal City in Arlington, VA. It comes highly recommended and I have not read a bad review yet. I hope the trees are still nice at that time...who knows with the weather we have been having this year! I've been to DC 3 other times with an 8th grade group. I'm glad to not be going with 400 kids this time! We too have a lot planned. I've been studying the metro map and doing some planning that way. Email if you wish...hope you have a great time!!