seriously...50 cents... Correction. 1964 (90% silver) - about $6 as of 06/2009 1965-69 (40% silver) - about $2.50 as of 06/2009 1971-present (copper-nickel) - no added value.
Gilroy Roberts designed the obverse of the coin, the letters are his initials.
Kennedy half dollar coins were made from 1964 to present, so, so far 46 years. They are still being produced.
The 50 cent coin bears the head of President John F. Kennedy
From mid-19th century to 1964 : 12.5 grams 1965-69 : 11.5 gm 1971-present : 11.3 gm