Penny Black: ‘First’ piece of mail sent using a stamp could fetch up to $2.5 million at auction
The first known piece of mail sent using a prepaid stamp — “one of the greatest leaps forward in human communication” — could fetch between $1.5 million and $2.5 million when it comes up for auction at Sotheby’s in New York next month. If the piece realizes its estimate, Sotheby’s said it would become one…