This museum is, somewhat surprisingly, a hit, a pleasant hour spent for the whole family. Bring your address book and you can send postcards to the folks back home through an interactive exhibit that issues a cool postcard and stamps it. That's just one feature that makes this museum visitor-friendly. Many of its exhibits involve easy-to-understand activities, like postal-themed video games.

The museum documents America's postal history from 1673 (about 170 years before the advent of stamps, envelopes, and mailboxes) to the present. (Did you know that a dog sled was used to carry mail in Alaska until 1963, when it was replaced by an airplane?) In the central gallery, titled Moving the Mail, three planes that carried mail in the early decades of the 20th century are suspended from a 90-foot atrium ceiling. Here, too, are a railway mail car, an 1851 mail/passenger coach, a Ford Model-A mail truck, and a replica of an airmail beacon tower. In Binding the Nation, historic correspondence illustrates how mail kept families together in the developing nation. Several exhibits deal with the famed Pony Express, a service that lasted less than 2 years but was romanticized to legendary proportions by Buffalo Bill and others. In the Civil War section you'll learn about Henry "Box" Brown, a slave who had himself "mailed" from Richmond to a Pennsylvania abolitionist in 1856.

The Art of Cards and Letters gallery displays rotating exhibits of personal (sometimes wrenching, always interesting) correspondence taken from different periods in history, as well as greeting cards and postcards. And an 800-square-foot gallery, called Artistic License: The Duck Stamp Story, focuses on federal duck stamps (first issued in 1934 to license waterfowl hunters), with displays on the hobby of duck hunting and the ecology of American water birds. In addition, the museum houses a vast research library for philatelic researchers and scholars, a stamp store, and a museum shop. Inquire about free walk-in tours at the information desk.

Opened in 1993, this most recent addition to the Smithsonian complex occupies the lower level of the palatial beaux arts quarters of the City Post Office Building, which was designed by architect Daniel Burnham and is situated next to Union Station.