It was established through joint agreement between the United States Postal Service and the Smithsonian Institution and opened in 1993.

The museum's atrium features vehicles used to deliver mail throughout the history of the USPS, including planes, trains and automobiles.

[4] Historical exhibits guide visitors through the postal service's inception and expansion, as well as its role in significant national events such as World War II.

[8] From June 2015 until December 2019, the museum displayed the 1856 British Guiana 1c magenta, the world's most valuable stamp, which sold for nearly $10 million.

[9] In September 2009, the museum received an $8 million gift from investment firm founder William H. Gross to help finance an expansion project.