The U.S. didn't make any half dollars dated 1804.
no NO U.S. coins were ever made of pure silver. All had at least 10% copper in them. NO U.S. half dollar is worth a megabuck. Perhaps you are thinking of the famous 1804 silver dollar, which does sell for over that amount.
HALF a dollar - $0.50
A 1969 silver Kennedy half dollar is worth $5 inn perfect condition. The value of the silver is worth $2.87.
The 1966 Kennedy half dollar is 40% silver and worth about $5.00.
If you mean a 1998 Kennedy half dollar, the coin has no silver in it and is worth face value.
If the coin is a US Kennedy half dollar dated 1974 it has no silver in it and is face value.
Kennedy is on the HALF dollar, not dollar. There were no U.S. silver dollars minted in the 1960s. The '64 Kennedy half is 90% silver and extremely common, currently worth about $10.50 for the silver.
Half dollar minted 1965-70 are 40% silver and currently worth around $4.
It's worth about $15.00 for the silver.
The coin is only 40% silver and has a value of $2.73 only the 1964 Kennedy half dollar was 90% silver.
A 1860 Liberty Seated Half Dollar in good condition (G4) is worth: $250.00.
About $5.00