The proof 1996 Silver Eagle does show a retail value of $29.00 for a Deep Cameo Proof
1 dollar
$20
The US did not mint a dollar coin in 1968, therefore you don't have a 1968-D silver dollar.
The U.S. didn't mint any silver dollars in the 1940s.
The Carson City Mint opend in 1869
A typical Mint State coin is about $50.00
as much as you can get for it.
The U.S. didn't mint any silver dollars in 1946.
There were no silver dollars issued by the US Mint in 1964.
A 1884 Silver Dollar - aka - Morgan Dollar - is worth in good condition (G4): $18; if its mint state is MS60, the value rises to: $40.
It is worth about $10 in good condition and about $20 in mint condition.
A 1901-S Silver Dollar - aka - Morgan Dollar - is worth in a mint state of AU50: $225.00.