Did you know that the U.S. Postal Service provides stamps through the Internet, by mail and automatic teller machines and through more than 21,000 private retail outlets? It handles 46 percent of the world's card and letter mail volume. It transports mail by plane, truck, rail, boat and even by mule, to and from the bottom of the Grand Canyon.
The shapes of stamps
U.S. stamps have been issued in many shapes. A diamond shape was featured in the $5 George Washington and Andrew Jackson stamps of 1994. A triangle stamp was used for the 32-cent Pacific 97 Sailing Ship and Stagecoach in 1997.
A circular stamp depicted the $11.75 Space Achievement and Exploration hologram in July 2000. A pentagonal stamp illustrated the Solar System in 2000.
Four commemoratives have been issued by Ireland in its aviation series. The stamps depict military aircraft: the Hawker Hurricane and Bristol fighter, both 30 pence, and De Havilland Vampire and the Sud Alouette, each 45 pence.
The aviation series was launched in 1998 to honor Irish aviation pioneers and followed with a salute to commercial aviation in 1999.