There have been 6 cent postage stamps available almost since there were first postage stamps. Assuming you meant to ask "When did it cost 6 cents to mail a letter?" the answer is: In the U.S. from 7 January 1968 through 15 May 1971.
{| |- | There were many 6 cent stamps available, long before the cost of a letter was 6 cents. First Class postage in 1968 was 6 cents for the first ounce. This rate was valid through May 1971. At that point it went up to 8 cents. |}
US first class stamps sold for 6 cents from the beginning of 1968 until May 1971 when the rate went up to 8 cents.
Postage in beginning January 7, 1968 was 6 cents. It was 5 cent until then. It went up to 8 cents in May of 1971.
The US has had 6 cent stamps available for over 100 years. The postage rate was 6 cents from January 1968 through May of 1971. At that point a postcard was 6 cents.
The sheet version came out Dec. 29, 1966.
The coil that is the same design as the sheet version came out Dec, 28,1967.
The smaller coil version was issued Feb 28,1968.
It was 2 cents for First Class Postage until 6 July 1932 when the postage rate increased to 3 cents.
A postage is 45 cents.
The current cost of a US postage stamp is 44 cents
There was never a 12 cent stamp for regular postage. It went from 10 cents to 13 cents on 12/31/1975. There was however a postage card stamp for 12 cents in 1981.
The G make up rate stamp can still be used for 3 cents of postage. The dove stamp was issued in 1995 when postage went from 29 cents to 32 cents.
The G rate dove stamp was issued in 1995 when postage went from 29 cents to 32 cents. The make up rate stamp can still be used for 3 cents of postage.
A first class postage stamp is $0.50 or 50 cents.
The current value for a standard postage stamp is 46 cents.
Right now, a postage stamp is 44 cents.
The cost of a First Class US postage stamp in 1968 was 5 cents. It was raised to 6 cents on January 8th. It stayed at 6 cents until 1971 when it went to 8 cents.
In 1969 it would have been 6 cents for first class postage. A post card would have been 5 cents.
The current price of a postage stamp is .49 cents. It was increased from .46 cents on January 27, 2014.