The value of an 1840 US half dime depends on its condition and the specific variety of the coin. The catalog values for the 1840 US half dime coin in different grades are as follows:
* Good (G): $50
* Fine (F): $70
* Very Fine (VF): $90
* Extremely Fine (XF): $125
* Uncirculated (UNC): $150
In addition to the condition, the value of an 1840 US half dime can also be affected by its rarity and desirability among collectors. Some varieties of the coin, such as those with certain mint errors or unique design elements, can command higher prices.