Some 1940s silver dollars are more valuable than others. For example, the 1943-S Walking Liberty half dollar is a key date coin and is worth significantly more than other 1940s silver dollars. The 1943-S Walking Liberty half dollar was minted in San Francisco and is characterized by its small "S" mint mark. Only 270,000 of these coins were minted, making them relatively scarce.
The condition of a 1940s silver dollar is also an important factor in determining its value. Coins that are in mint condition (MS) or proof condition (PR) are worth more than coins that are circulated or damaged. The Sheldon grading scale is used to assess the condition of coins, with MS-70 being the highest grade possible.
If you have a 1940s silver dollar, it is important to have it appraised by a professional coin dealer to determine its exact value.