$2,040,500 The Alexandria “Blue Boy” is a rare Postmasters’ Provisionals stamp produced in Alexandria, Virginia (then part of the District of Columbia) in 1847. What makes it unique is its color—it’s the only specimen printed on blue paper among the seven known Alexandria provisionals. The other six are printed on buff paper. This remarkable stamp remains affixed to its original envelope, which was canceled with a “PAID” handstamp. (Getty Images)