USPS Cover Stamps of "Wonders of America"

USPS on 27 May 2006 chose 40 American natural and man-made superlatives - the tallest, the loudest, the oldest, the longest, the deepest, the largest, the windiest, the hottest, the fastest - to create a colourful set of stamps related to the "Wonders of America". Avery Dennison printed 204,000,000 copies of these bold, multicoloured stamps, using a Photogravure printing method with a Serpentine die cut 10 ¾. The First Day Cover issue originated from Washington, D.C. Shown here on this cover are four of those stamps.