Here’s a look at some of the 12 most valuable American ... after American stamps. This set represents the dawn of airmail service in the U.S., a significant milestone in postal history.

The stamp, seen here with Siegel Auctions President Scott Trepel, once famously featured in an episode of the Simpsons A rare US postage stamp has sold for $2m (£1.63m) in a New York auction ...

These are the most valuable ... The only known stamp of its kind, the Alexandria Blue Boy is a circular blue stamp issued in 1847 or 1846 (it’s said to have been used as postage for a love ...