The Postal Service commemorated the 150th anniversary of the Smithsonian Institution with the issuance of a 32-cent stamp on February 7, 1996, in Washington, DC.
Designed by Tom Engeman of Carbondale, Colorado, the stamp features the Smithsonian Institution Building, more commonly known as the Castle. The Castle, the first Smithsonian building built, was designed by architect James Renwick and constructed between 1847 and 1855. The Smithsonian Institution, which is composed of an education and research complex of 19 museums, 9 research centers, and the National Zoo, was established in its present form on August 10, 1846, by an Act of Congress signed by President James K. Polk.
The stamp was issued in a pane of 20, and printed by Ashton-Potter (USA) Ltd. in the offset process.
Reference: Postal Bulletin (January 4, 1996)