What was the price of postage stamp in the US in 1978?

Answer 1

For the years 1978 & 1979 the cost of postage was 15 cent.

Answer 2

It was 13 cents for first class postage until May 29, 1978, when it went up to 15 cents.

Answer 3

{| |- | First Class postage in 1978 was 13 cents for the first ounce. This rate was valid through Mid-year. At that point it went up to 15 cents. |}