Actually, these aren't coins either â€" they are medals. Yes, they were struck by the US Mint, but that doesn't automatically make them coins. The US Mint has struck coins AND medals for roughly 200 years. Medals have no monetary value, i.e., they can't be used like coins to buy things.
What you have are what are termed as "List Medals" of the US Mint. They are so named as they were part of a list of medals that the Mint offered for sale at various times.
In terms of value, many of the medals that are no longer offered by the Mint sell for $30 and up, depending on the medal's subject â€" some are more popular than others. Some of these medals can sell for over $50 while others go wanting at $15.
I would suggest visiting
ebay. Navigate to the Medals section under Coins\Exonumia and use
ebay's search feature to check out current and previous auctions of the same medals. It would be best if you use the "Completed" auctions (available as part of
ebay's Advanced Search) to get prices for medals that actually sold. Often, sellers list these medals at higher prices than collectors are willing to pay in hopes of "scoring" so they are not the best examples to use when trying to get a sense of a medal's current market value.
Good luck!
PS I've sent a note to the Admin to move this thread to the Medals section here on CCF.