How America Got Its First Postage Stamps
The adoption of adhesive postage stamps in 1847, for use in the prepayment of postage on mail matters, represented one of the most single improvements in the history of the Postal Service in America. As provided by law, these stamps were designed to be issued to postmasters on account, for sale to the public, thereby providing an accurate and automatic check on the postage revenues, in lieu of the less uniform and more uncertain methods that had prevailed in the past.
Prior to the issuance of the first stamps, letters accepted by postmasters for dispatch were marked “PAID” or “DUE”, by means of pen and ink or hand stamps of various designs. Such letters usually contained the town post mark and date of mailing.
To facilitate the handling of mail matter for use on letters, some postmasters provided special stamps or devices for use on letters as evidence of pre-payment of postage. These stamps of local origin are known as “Postmasters’ Provisionals”. After the introduction of postage stamps, these various methods of mailing without stamps affixed continued to be legal until the prepayment of postage by means of stamps of governmental issue was made obligatory by law, effective January 1st, 1856.
As soon as possible after the enactment of the law on March 3rd, 1847, authorizing the issuance of adhesive postage stamps, contracts was entered into with a private manufacturer for the printing of the quantities required for placing on sale July 1st, 1847. Subsequent contracts for postage stamps continued to be awarded to private manufacturers until July 1st, 1894, on which date the printing of stamps was transferred to the Bureau of Engraving and Printing, Treasury Department.
Source: The above is taken from Post Office Department Publication 9, Postage Stamps of the United States 1847-1955.