This stamp commemorates the Sixth International Philatelic Exhibition (SIPEX) held in Washington, D.C., May 21-30. A souvenir sheet was also issued for the event.
1966 SIPEX 5c Multicolored
US Stamp Catalog
An online listing of US Postage Stamps
An online listing of US Postage Stamps
This stamp commemorates the Sixth International Philatelic Exhibition (SIPEX) held in Washington, D.C., May 21-30. A souvenir sheet was also issued for the event.