I don't know how old your kids are, but we took our boys to DC when they were 9 and 11 years old (or maybe 8 & 10). Our most favorite activity was a "Bike the Sites" tour we did. We met our group (about 10 of us) and our guide ( a young, fun guy who had a masters in U.S. History - he may have actually been the owner of the company) at a prearranged spot on the Mall. He had our bikes and helmets ready, and we followed him on a bike ride around the Mall and over the Jefferson Memorial, and the Capitol, etc. Our guide talked about the history of the various buildings around the Mall and what each one housed. We road through an outdoor sculpture garden and saw cool fountains. He knew so much about the various memorials (Lincoln, Jefferson, Vietnam, Korean, etc.) - things we never would have known. We took a break at the Einstein statue and the kids sat on Einstein's lap and ate fig newtons, which they still love to this day and which they always associate with our trip to DC. (They are now 16 & 17). We finished the trip at the Washington Monument and then had a wild fast ride down the hill. Very fun. I would HIGHLY recommend for anyone, but especially families with kids.