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.
If you mean a 1998 Kennedy half dollar, the coin has no silver in it and is worth face value.
The 1966 Kennedy half dollar is 40% silver and worth about $5.00.
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.
If the coin is a US Kennedy half dollar dated 1974 it has no silver in it and is face value.
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