I agree with Spence that you have a 1964
Kennedy half dollar that someone placed later in a non mint holder for presentation. The 1964
Kennedy half dollars are among the most sought after of all 90% silver coins and have a value also from the silver. the U.S. Mint changed the composition of the dime and quarter to a copper-nickel clad format while reducing the silver content of the half dollar to 40% beginning in 1965. When uncirculated only, some higher quality examples may be worth looking at grading as top examples can be worthwhile to do so, but otherwise is just a nicely presented kennedy.
T
here are a few varieties also, a couple mentioned here that can add value if they exist on the coin:
https://www.PCGS.com/news/1964-kenn...ilver-halves