Located in Washington DC, USA, the National Postal Museum was established through joint agreement between the US Postal Service and the Smithsonian Institution. It was opened in 1993 and is located across the street from Union Station. The building that once served as the main post office of Washington, is now the home of the museum. The building served as the Washington DC postal service from 1914 until 1986. The building was designed by Graham and Burnham architectural firm. It was led by Ernest Graham following the death of Daniel Burnham in 1912.

The museum holds many interactive displays about the history of the US Postal Service and of the postal service around the world. The museum has a vast collection of stamps which are also on display. 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, and even 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. Since 2002 the museum has presented the Smithsonian Philatelic Achievement Award every two years.

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