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. Postal delivery in the United States was a matter of haphazard local organization until after the Revolutionary War, when eventually a national postal system was established. Stampless letters, paid for by the receiver, and private postal systems, were gradually phased out after the introduction of adhesive postage stamps, first issued by the U.S. government post office July 1, 1847, in the denominations of five and ten cents, with the use of stamps made mandatory in 1855.