Some are firsts, others have printing errors and others are simply rare and old—all factors that make these the most sought-after U.S. stamps.
In the early days of U.S. parcel service, there weren’t clear guidelines about what you could and couldn’t mail.
Stamps have often invited debate—usually for reasons the post office never anticipated.
The 1970 postal strike brought the nation to its knees.
Following yesterday's decision to end Saturday mail delivery, find out more about the long history of the U.S. Postal Service.