You forgot that one.
The removal of silver from coins came after Kennedy:
The Coinage Act of 1965, Pub.L. 89–81, 79 Stat. 254, enacted July 23, 1965, eliminated silver from the circulating United States dime and quarter dollar coins. It also reduced the silver content of the half dollar from 90 percent to 40 percent; silver in the half dollar was subsequently eliminated by a 1970 law.