The National Museum of Natural History has the Hope Diamond, but the National Postal Museum has the envelope wrapping used to mail the gem to the Smithsonian—part of a collection that consists of more than 6 million stamps. Exhibits, underscoring the important part the mail has played in America's development, include horse-drawn mail coaches, railroad mail cars, airmail planes, and a collection of philatelic rarities. Learn about stamp collecting and tour Systems at
Work, an exhibit that demonstrates how mail has gone from the mailbox to its destination for the past 200 years, featuring a high-def film highlighting amazing technologies. The Mail Call exhibit shows the history of the military postal system from the Revolutionary War to today, including a video entitled "Missing You—Letters from Wartime." The William Gross Stamp Gallery, the largest of its kind in the world, has an additional 20,000 objects never before on public display, showing how closely stamps have intertwined with American history. The museum is housed in the old Washington City Post Office, designed by Daniel Burnham and completed in 1914. Nostalgic odes to the noble mail carrier are inscribed on the exterior of the marble building; one of them, "The Letter," eulogizes the "Messenger of sympathy and love / Servant of parted friends / Consoler of the lonely / Bond of the scattered family / Enlarger of the common life."