Strong, soil-resistant Whitman albums with blue textured leatherette cover are designed with thumb notches for easy window removal. 112 ports. One of the most beloved U.S. coins, the Kennedy half dollar vanished from circulation soon after their release in 1964. Its valuable silver along with a feeling of grief by the recent Kennedy's assassination made the coin impossible to circulate. In order to alleviate the problem, the U.S. Mint changed the composition from 90% silver and 10% copper as seen in the 1964 coins to 40% silver and 60% copper for the ones struck from 1965-1970. The change failed and the coins were still rarely seen in public. As a consequence, silver was completely eliminated, and from 1971 to Date the coins have a pure copper inner core and an outer layer made of 75% copper and 25% nickel. A special coin to commemorate the Bicentennial was struck in 1976. All Kennedy half dollar coins measure 30.6 mm in diameter. Their weight went from 12.50 grams in 1964 to 11.50 grams from 1965-1970. Kennedy half dollars now weigh 11.34 grams.