Do this first
Want to see democracy in action? Tours are free, but you need reservations.
Capitol: Request up to three months before your visit at visitthecapitol.gov or through your senator or representative. Some same-day passes available.
House and Senate in action: Request gallery passes through your senator or representative
Where to stay
Choose a hotel near a metro stop or within walking distance of your main destinations.
"The L'Enfant Plaza makes a great home base. It's two blocks from the Smithsonian National Air and Space Museum and has an outdoor pool," says Candyce Stapen, creator of the Washington DC with Kids app. (Weekday rates start at $229, weekends at $189; parking starts at $50; package options available; lenfantplazahotel.com; 202-484-1000.)
Parking in DC is pricy and hard to find, so leave the car at home or at your hotel and ride the Metrorail (one-way fares start at $1.60 for ages 5 and up; wmata.com).
Another option: tour on two wheels like the Lacanienta family of Las Vegas, Nevada. "Our kids loved biking between the memorials and museums, and we saw more of the area because it took less time (about three hours to tour the memorials) than walking," says mom Chantelle. They rented bikes and helmets from Bike and Roll on the National Mall (bikethesites.com; 202-842-2453).
Where to eat
On the go: More than 100 food trucks offer everything from crepes to kabobs, burritos to bratwurst (foodtruckfiesta.com).
Sit-down: Capitol Hill's historic Barracks Row district (8th Street, SE) is full of family-friendly options (barracksrow.org). "Ted's Bulletin is a standout, with big booths, a nice kids' menu, and an old-time cartoon playing on one wall," says blogger Linda Samuel of kidfriendlydc.com.
Just desserts: The Sweet Lobby on Capitol Hill recently won the Food Network's Cupcake Wars (sweetlobby.com), but there are plenty of other cupcakeries angling for your vote, including Sprinkles (sprinkles.com) in Georgetown -- sadly, not on the metro line -- and the roving Curbside Cupcakes trucks (curbsidecupcakes.com). Craving cooler fare? Sugar Magnolia, a new bakery in Cleveland Park, near the National Zoo, offers homemade ice-cream sandwiches in eclectic flavors, such as maple-bacon ice cream, bookended by waffles (rippledc.com).