It wasn't issued in 1913 - it was issued between 1981-1984 as part of a series. It's worth about .20 cents mint and used.
One 20th of a dollar
Barely, probably the face value of the stamp.
The D stamp has a face value of 22 cents and can be used on domestic mail at that value.
Forever
15 cents.
value is 25 cents
The F series stamps were issued in 1991. The postage stamp has a face value of 29 cents.
The current value for a standard postage stamp is 46 cents.
The value of US commemorative stamps varies depending on type and issue guide. They can range anywhere from a minimal value for a used stamp to thousands of dollars for a rare mint condition stamp. There are many US stamp price guides that can be obtained to find out a catalog value. Stamps in the US that are unused can always be used for face value as postage.
4 cents
According to the website United States Non-denominated Stamp Values, the face value is 37 cents.
The F series stamps were issued in 1991. The postage stamp has a face value of 29 cents.