What is the value of a silver quarter dollar in mint condition be worth issued in the year 1788 with a picture of ships on the back?

Uh, did you look beyond the "1788" date to see that the coin also carries the date 2000, the year it was issued to mark the admission of Virginia to the U.S.? EVERY SINGLE ONE of the State Quarters carries two dates, the date the coin was struck and the date the state was admitted to the Union.

And ...

it's not silver, either. Look at the edge. It's made of copper and nickel, and is only worth 25 cents, just like all the other dozens of billions of state quarters in circulation.