How much is a 1819 silver dollar coin worth?

The U.S. did not mint any $1 coins for circulation from 1804 to 1835 inclusive.

If you have a "dollar" dated 1819 it's either a privately-minted piece, a fantasy piece, or a counterfeit.

Please check again and post a new question with the corrected date and/or denomination, and a more complete description.