If what you have is a 1999 Silver American Eagle it is certainly worth more than one dollar. It is one ounce of pure silver. It is worth $3 to $5 over the spot price of silver. The spot price is currently around $14 per ounce. So that would make your coin worth at least $17. The only other dollar coins made that year would be a Susan B. Anthony dollar and that issue is not silver. It is a copper-nickel clad coin. If it is circulated, it is not worth more that $1, if it is in mint condition, it may be worth $3 - $5. The proof version of the 1999 SBA could be worth $30 - $40.
I think they tried to make Susan B.Anthony dollars in 1999. If I had to guess it would be around 1.10. They are a little rare I guess
Lady painted in blue,white and red. Silver coin 1999
As you have not mentioned the coin category ,still you can browse the following website and get your required answers.
I would say if it is only 1999, it is still only worth a dollar, because no significant time amount has passed.