After the assassination of President Kennedy in 1963, the wheels were quickly set in motion to produce a coin in his honor. The half dollar denomination was chosen and in 1964, the first JFK halves entered circulation. Not only was the 1964 Kennedy half dollar the first of the series, but it was also the last 90% silver coin issued for commerce. Silver prices began to rise in the 1960s and soon exceeded the face value of coinage. After 1964, the Kennedy half dollar's silver content was reduced to just 40%. Silver was entirely removed from circulating coins after 1970.