The Smithsonian's National Postal Museum opens its new William H. Gross Stamp Gallery to the public Sunday, Sept. 22. Named after its primary benefactor, it is the world's largest stamp gallery and the only one to show stamps and mail in the context of American history and culture. It provides an experience available nowhere else and offers something for everyone-from casual visitors to experienced collectors.

Among the gems on display: a cover postmarked on the moon in 1971; a watch worn by a sea clerk aboard Titanic; one of two 1868 1-cent Z-grill stamps in existence (with the image of Benjamin Franklin, the nation's first postmaster general); a letter addressed to John Hancock postmarked July 4, 1776; stamps depicting kings of Hawaii before it became a state; and the icon of the Smithsonian's stamp collection-the Inverted Jenny-will be shown along with other stamps from America and around the world.

A wall of exterior windows overlooking Massachusetts Avenue, depicting reproductions of 54 historic U.S. stamps, provides a dramatic nighttime glow and is a preview of what is inside the museum's 12,000 square feet of new exhibit space. Special family activities, tours and programs will be offered throughout the day; from 10 a.m. until 5:30 p.m.

To read the complete article, see:World's largest stamp gallery opens at the National Postal Museum(artdaily.com/news/65140/World-s-largest-stamp-gallery-opens-at-the-National-Postal-Museum#.Uj435Maa7C8)

For more information on the galley, see:National Postal Museum(www.postalmuseum.si.edu/)