How much is a napoleon 3 rd 1868 5franc coin worth?

The U.S. did not make any silver 5-cent coins after 1873.

If you have a U.S. nickel coin with that date (Miss Liberty on the front, the Roman numeral V on the back) as of 10/2008 its retail value is about $4 in worn condition, $20 with moderate wear, up to $60 in almost new shape.

If you have a coin from Another Country please post a new question. There are subcategories for different countries so posting there will be helpful.