The U.S. has had 25 cents postage stamps during most of the time there have been stamps. Assuming you meant to ask "When did it cost 25 cents to mail a letter?" the answer is from 3 April 1988 through 2 February 1991.
The rate went to 20 cents on 1 November 1981. A second ounce was 17 cents. It stayed at that rate until February 22, in 1985.
{| |- | First Class postage was 25 cents for the first ounce beginning in April 3 1988. This rate was valid through February 1991. At that point it went up to 29 cents. |}
1969
First class postage was 33 cents for the first ounce in 2000. A post card cost 20 cents.
The cost for the first ounce of postage in 1982 was 20 cents. It had been at that rate sinceNovember 1, 1981.
Depends what country you are from. this is a world wide site, you could be asking this question anywhere in the world.
A= 15 cents B= 18 Cents C= 20 cents D= 22 cents E= 25 cents F= 29 cents G= 32 cents H= 33 cents
First class stamps in 1996 cost 32 cents in the US. A post card was 20 cents.
A First Class Postage Stamp in 1987 was 22 cents.
That was issued in 1981 when postage went from 18 cents to 20 cents. It can still be used for 20 cents worth of postage.
First class postage rate was 33 cents for the first ounce. Second ounce was 22 cents. A postcard cost 20 cents. This question depends on which country you live.
20 stamps
They are still valid as postage, however, they are only worth 20 cents, which means you would need two of them plus another 4 cents to mail a letter.
This is a common stamp which is easily obtainable. No stamp in good condition is worthless to a collector. Mint US stamps always worth their face value if one can find use for them for postage. The minimum retail price for single stamps varies with the dealer but is around 15 to 25 cents. Common mint stamps retail for about twice face if this is more than the minimum. As for selling common stamps-- dealers do not buy them one at a time. They get them by buying collections or accumulations of thousands of stamps. They usually have all the common stamps they can sell because they get them along with the scarcer stamps.
They are still valid as 20 cents worth of postage. You would have to add additional stamps to the envelope to meet the correct rate.