First United States postage stamp was issued in 1847, eight years after The Penny Black, the world’s first postage stamp. In 1847 March 3rd Congress approved and authorized The first stamp issues. The first issue included two imperforate 5 cent Benjamin Franklin and a 10 cent George Washington stamp. Exactly release dates are not known but the earliest known use of the Franklin 5 cent stamp was on July 7th. earliest known use of the Washington 10 cent stamp as on July 2th, 1847.
These stamps are not very rare so 5 cent stamp in very fine condition can be bought for around $2500 (Mint) and $400 (used). 10 cent used stamp in fine condition cost around $750-$1500.
1875 these stamps were reprinted so if you are buying these make sure you know which issue you are buying. A mint 1875 5 cent stamp very fine condition is priced around $750.
Even thought these two are the first official US federal government issued stamps, there were several stamps issued by provincial governing bodies and institutes. In February 1842 private carrier service called ” City Despatch Post ” started operating in New York introduced the first adhesive postage stamp ever produced in the western hemisphere.