1. Grade and Condition: The condition of the quarter is an important factor in determining its value. Quarters in uncirculated condition, with no signs of wear, can be worth more than those that are circulated.
2. Rarity and Mint Mark: The mint mark on a quarter (which can be located below the eagle on the reverse) can indicate the mint where it was produced. Quarters from certain mint locations, such as the San Francisco mint (marked with an "S" mint mark) or the Philadelphia mint (marked with no mint mark), may have lower mintages and be more valuable.
3. Errors: Quarters with errors, such as off-center strikes, doubled dies, or other mint errors, can also have increased value.
4. Numismatic Value: Some 1943 quarters may have additional numismatic value due to their historical or sentimental significance. For example, quarters from that era may have been used in wartime activities, adding to their historical significance.
Overall, the value of a 1943 US quarter can range from as low as 50 cents to several hundred dollars, depending on the factors mentioned above. If you have a 1943 US quarter, it is a good idea to consult with a coin expert or an experienced dealer to determine its accurate value.