Postage stamps and postal history of the United States

Postal service in the United States began with the delivery of stampless letters whose cost was borne by the receiving person, later encompassed pre-paid letters carried by private mail carriers and provisional post offices, and culminated in a system of universal prepayment that required all letters to bear nationally issued adhesive postage stamps. In the earliest days, ship captains arriving in port with stampless mail would advertise in the local newspaper names of those having mail and for them to come collect and pay for it, if not already paid for by the sender.

Source: Wikipedia — Postage stamps and postal history of the United States (CC BY-SA 4.0)