Smithsonian's National Postal Museum, Washington, United States

The Smithsonian's National Postal Museum is devoted to presenting the colorful and engaging history of the nation's mail service and showcasing one of the largest and most comprehensive collections of stamps and philatelic material in the world.

The National Postal Museum, located opposite Union Station in Washington, D.C., United States, was established through joint agreement between the United States Postal Service and the Smithsonian Institution and opened in 1993.

The museum is located across the street from Union Station, in the building that once served as the Main Post Office of Washington, D.C. from 1914, when it was constructed, until 1986. The building was designed by the Graham and Burnham architectural firm, which was led by Ernest Graham following the death of Daniel Burnham in 1912.

The building in which the museum is housed, also serves as the headquarters of the United States Department of Labor's Bureau of Labor Statistics as well as a data center for the United States Senate.

The museum houses many interactive displays about the history of the United States Postal Service and of mail service around the world. Also on display is a vast collection of stamps. The museum houses a gift shop and a separate stamp shop, along with exhibits on the Pony Express, the use of railroads with the mail, the preserved remains of Owney (the first unofficial postal mascot), and an exhibit on direct marketing called, "What's in the Mail for You," that produces a souvenir envelope with your name printed on it and a coupon for the gift shop. As a Smithsonian museum, admission is free. This museum also houses a library.

In 2005, the museum acquired John Lennon's childhood stamp collection.

In September 2009, the museum received a $8 million gift from investment firm founder William H. Gross to help finance the expansion of the museum. The museum now hosts the William H. Gross Stamp Gallery named in his honor.

Since 2002, the museum has presented the Smithsonian Philatelic Achievement Award every two years.