Treasures from the William H. Gross Collection

In honor of National Stamp Collecting Month, the museum features three great stamp rarities on loan from William H. Gross, founder of PIMCO: a block of four 1918 "Inverted Jennys"; a cover from the Pony Express Service; and a cover featuring the 10-cent George Washington stamp, dated July 2, 1847.

• 1918 24-Cent "Inverted Jenny" Air Post Block of Four: The blue biplanes were printed upside down on the first sheet of 100 stamps; this inversion is one of the most recognizable stamp errors ever discovered.
• 1860 Pony Express Cover Recovered from Mail Stolen by American Indians: This cover was carried via the famous Pony Express service from San Francisco to New York City. However, American Indians in Nevada disrupted the delivery and overtook the rider. The letter pouch was subsequently recovered on the plains several years later, and the letters were ultimately forwarded to their destination.
• July 2, 1847, Envelope: The Earliest Recorded Use of a U.S. Postage Stamp: On July 1, 1847, the first stamps produced by the U.S. government were issued to the general public, including the 10-cent stamp featuring George Washington that was used to mail this envelope.

These rarities will be featured on long-term loan in the upcoming William H. Gross Stamp Gallery, which is expected to open in 2012. He recently made a generous donation of $8 million in September 2009 to create a new gallery that will be named in his honor.