The U.S Postal Service is celebrating the 50th anniversary of the Woodstock Festival with a colorful Woodstock Forever stamp designed to represent the peace and music of the festival. The stamp was dedicated on Aug. 8 at a First Day of Issue event held at the Metropolitan Museum of Art in New York City. “Woodstock was the most famous rock festival in history,” said Kevin McAdams, vice president of Delivery and Retail Operations for the U.S.