The US issued a number of postage due varieties. It will require some research to determine which version you have. A catalog will assist with the ID and will provide an estimated value.
Currently it's one 44 cent stamp. But the postage rates are due to go up soon, so the cost of the stamp will change when it does.
The value of a 4 cent black and white Freedom of the Press US postage stamp depends on its condition, rarity, and demand among collectors. In general, most stamps from that era are valued at less than face value due to their common nature.
There is a good chance the post office will deliver it. However, it may come back postage due.
Brazil was the second country to use adhesive postage stamps, issuing its first stamp in 1843. The stamp was known as the "Bull's Eye" due to its design.
They are still valid for postage in the US. The total stamp value must equal the current First Class rate. You would have to add 7 cents to each of them to total the correct amount for a letter. Used together they would cover two ounces of First Class mail.
{| |- | Scott Number J95. This was issued in 1959. You can purchase one of these for 20 cents used and mint from a dealer. This minimum value indicates that it has no real value. Consult a stamp catalog such as Scott's, for a description on how stamps are rated and graded. |}
In the 1970s, the cost of a postage stamp in the United States varied throughout the decade. At the beginning of the 1970s, a first-class stamp was 6 cents, but by the end of the decade, it had increased to 15 cents. This period saw several price changes due to inflation and rising postal service costs.
As long as it meets the postage due, it can be done with a single stamp.
An attempt will be made to return the mail to you indicating that there is insufficient postage or the letter will be forwarded to the address with postage due.
It is BUT the machines that read the stamps might show it as being cancelled and it could be returned to sender or be presented as postage due.
Stamps issued this recently aren't really worth much more (if anything) than the face value. I would recommend to just use it on your mailings! Being a stamp collector, the value of this stamp isn't very much due to it's young age and amount of it on the market place.
United States Scott #J92. You can purchase a used copy for 20 cents. A mint, or unused, copy would be 25 cents.