How much is a 1787-1999 US quarter dollar worth?

Answer 1

Uh, please look at your pocket change. ALL of the state quarters have double dates on them, one for the year the coin was minted and one for the year that the coin's state was admitted to the Union. That means you have a coin honoring Pennsylvania, Delaware, New Jersey, etc. because they were admitted in 1787.

Billions of each of these have been made, so your coin is worth the same amount as all of the other state quarters out there, 25 cents.