Grab breakfast downtown or on Capitol Hill at the homespun Lincoln’s Waffle Shop (504 10th St. NW, 202/638-4008) across from Ford’s Theatre or Teaism Penn Quarter (400 8th St. NW, 202/638-6010, www.teaism.com ) for healthier fare like Irish oatmeal and muesli.
Hit the National Archives  at opening for a look at the Declaration of Independence, the Constitution, and the Bill of Rights, as well as a 1297 copy of the Magna Carta. These precious documents are faded, but their legacy endures.
Head eastward on Pennsylvania Avenue to the U.S. Capitol  to tour the historic building or, if you haven’t secured a timed ticket, to see the platform that held Lincoln’s casket and other interesting artifacts on display in the Capitol Visitors Center.
At lunchtime, grab takeout at Taqueria Nacional (400 North Capitol St. NW, 202/737-7070, www.taquerianacional.com ) or stop by the city’s best museum cafeteria, Mitsitam , in the National Museum of the American Indian  for indigenous cuisine like board-roasted salmon and pumpkin soup.
Next, it’s decision time. What museum suits your interests? The 1903 Wright Flyer that soared at Kitty Hawk, North Carolina, holds a place of honor in the National Air and Space Museum . If you prefer art, check out Raphael’s Alba Madonna and Monet’s Rouen Cathedral at the National Gallery of Art . Or head to the National Museum of Natural History  to see a Tyrannosaurus rex fossil, the Hope Diamond, rare butterfly species, meteorites, a coral reef, and more.
With preordered, timed ticket in hand, board the Washington Monument ’s elevator for a ride to a spectacular view, nearly 555 feet above the ground.
Continue your tour heading north for a White House  photo op. Drop in for a drink and nosh at the Old Ebbitt Grill (675 15th St. NW, 202/347-4800, www.ebbitt.com ) or a mint julep at Willard Hotel ’s Round Robin Bar, a historic spot where Mark Twain, Walt Whitman, and Ulysses S. Grant once relaxed.
Plan to catch a free show—music, dance, or theater—at 6 p.m. nightly at Millennium Stage in the Kennedy Center ’s splendid Grand Foyer, with its adjacent terrace overlooking the Potomac River.
After dinner, venture to see the spectacularly lit monuments through one of the companies that offers a “hop-on, hop-off” tour, or better yet, a private for-hire car for a really special evening.
Grab a quick breakfast sandwich or savory crepe at Café Tu-O-Tu (2816 Pennsylvania Ave. NW, 202/298-7777, www.cafetuotu.com ) in Georgetown or savor breakfast at pricey Seasons at the Four Seasons Hotel , an airy, elegant dining room favored by Washington diplomats.
Head toward the river and rent a bike or a kayak at Thompson Boat Center (2900 Virginia Ave. NW, 202/333-9543) or catch a cab to enjoy a short, beautiful hike around Roosevelt Island . Cyclists can head north through verdant Rock Creek Park  or south for a daytime glimpse of the monuments. Paddlers and hikers can enjoy the views of wooded Roosevelt Island.
Check out historic Georgetown for lunch and shopping. Upscale fashion, stylish home furnishings, and fancy footwear can be found in Urban Chic (1626 Wisconsin Ave. NW, 202/338-5398, www.urbanchiconline.com ), Cady’s Alley (3318 M St. NW., www.cadysalley.com ), and Hu’s Shoes (3005 M St. NW, 202/342-0202, www.shop.husonline.com ). The Tombs  is Georgetown University’s quintessential college bar, perfect for a pub lunch, or try a wood-grilled pizza and insalata mista at Pizzeria Paradiso .
Finish out the afternoon across the river from the Lincoln Memorial  at Arlington National Cemetery . Its 624 acres features the Tomb of the Unknowns, countless graves of military and civilian heroes, and Arlington House , the home of Robert E. Lee.
Catch a show at the Arena Stage  or head to U Street for live music, jazz at Bohemian Caverns , or the flavor of the night—reggae, pop, country, hip-hop, or rock—at the 9:30 Club . Top off the evening satisfying your late-night munchies with a chili half-smoke, DC’s uniquely local smoked sausage, at Ben’s Chili Bowl .
Depending on your interests, mood, or the age of your fellow travelers, view pandas, big cats, and gorillas at the National Zoo  or steel yourself for a heart-wrenching visit to the U.S. Holocaust Memorial Museum , with its permanent exhibit of more than 900 artifacts, films, and testimonies from the Nazi concentration and death camps.
If you’ve opted for walking among the animals at the zoo, consider eating lunch at Lebanese Taverna (2641 Connecticut Ave. NW, 202/265-8681, www.lebanesetaverna.com ) on Connecticut Avenue, dining on gyros, shawarma, and hummus, or if you’ve gone to the Holocaust Museum and still have the stomach to eat, check out the views and southern fare at Sou’wester in the Mandarin Oriental Hotel , sure to lift your spirits.
From the zoo, head up Connecticut Avenue to the Washington National Cathedral , the country’s second largest, with groomed grounds and landscaping, breathtaking stained glass, interesting Gothic architecture, and great gargoyles and grotesques.
If you are on the National Mall, stroll over to the Newseum  to peruse the day’s front pages and admire Pulitzer Prize-winning photos. Another option? Check out the city’s oldest art museum, the Corcoran , with its collection of American portraiture, landscapes, and photography.
Linger in the downtown area’s stores, and dine nearby on Mediterranean mezes at Zaytinya  or grab a burger, crab-cake sandwich, or a beer at Clyde’s of Gallery Place (707 7th St. NW, 202/349-3700, www.clydes.com ).
See if you can score tickets to a sporting event or concert at Verizon Center (601 F St. NW, 202/661-5000, www.verizoncenter.com ), home to the Washington Capitals, Mystics, and Wizards pro sports teams and the Georgetown men’s basketball team.
Sip a nightcap after the game or show at Proof , a wine bar with 40 wines by the glass.
The morning begins with fortifying sustenance from Bagels & Baguettes (236 Massachusetts Ave. NE, 202/544-1141, www.bnbcafe.net ) on Capitol Hill on the Senate side; bring cash for the tasty eggwiches, bagels, and “schmear.” Or sit down to enormous Belgian waffles at Jimmy T’s (501 East Capitol St. SE, 202/546-3646).
Jump in line to watch the U.S. Supreme Court  in action: stay for an entire procedure or opt for the three-minute quick-view line. If court is not in session, take in an informational video and wander the building’s vast halls.
Take in the exhibits, including a flawless Gutenberg Bible and Thomas Jefferson’s personal book collection, at the Library of Congress , the world’s largest book repository.
For lunch, drop by the House of Representatives’ Longworth House Office Building at the U.S. Capitol  and head to its cafeteria, with the widest menu selection of any congressional dining room and great people watching—congressional staff, representatives, lobbyists, the media, and more.
Burn off lunch by strolling down Capitol Hill to the U.S. Botanic Gardens , a tropical paradise with thousands of flowering plants, blooms, towering trees, a waterfall, hanging plants, and a canopy walk.
Check out the indoor and outdoor modern collection at the Hirshhorn Museum and Sculpture Garden ; its avant-garde works by artists like De Kooning, Ellsworth, Matisse, Calder, Warhol, and Rodin challenge conventional parameters. For more traditional portfolios, consider the quiet spaces of the Freer and Sackler  galleries, featuring a vast selection of Asian art as well as the world’s largest collection of James Whistler, and the National Museum of African Art , with an excellent collection of decorative arts from across the continent.
If art museums don’t tickle your fancy, spend the afternoon getting lost in the “nation’s attic,” the National Museum of American History .
Union Station  is worth a brief detour before dinner; the grand Main and East Halls of this massive beaux arts-style building, designed by Daniel Burnham, feature massive coffered ceilings, murals, columns, and statuary as well as shops and restaurants.
Enjoy the music and food of the Big Easy like char-grilled oysters, gumbo, and étouffée, as well as tastes from the Chesapeake Bay, including soft-shell crabs in season at Johnny’s Half Shell , a lively place to linger over a Sazerac.
Take the car, hire a cab, or if you’re fit, rent a bike for a morning trip to George Washington’s Mount Vernon , the first president’s impressive plantation home, eight miles south of Alexandria, Virginia . Don’t miss the gift shop, one of the area’s best.
Return to Alexandria, Virginia, to continue the colonial experience, dining at a favorite restaurant for the founding fathers, Gadsby’s Tavern , famous for serving Washington, Adams, Jefferson, and Madison.
Roam the streets of Old Town Alexandria, with more than 4,000 historic buildings, including Christ Church  and its graveyard and the Stabler-Leadbeater Apothecary Shop , where Martha Washington bought her medical supplies.
Window-shop along King Street before settling into a table at The Majestic , an art deco-style eatery serving locally-sourced down-home cooking, or dine in style at the nationally recognized Restaurant Eve . Or skip the fancy tabletops and head to The Birchmere (3701 Mount Vernon Ave., 703/549-7500, www.birchmere.com ) for a bar meal on red-checked tablecloths and an acoustic, jazz, blues, or country show.
If you’ve elected to stay in Old Town, hit up Murphy’s , an Alexandria Irish pub standard that has been around nearly 30 years, for a pint and the chance to pound on the tables while belting out a rambunctious rendition of “Red Rover.”