You probably have one of the bullion coins issued in recent years by the Mint. The "dollar" denomination is purely arbitrary; they're intended to be sold for their precious metal value and not be spent.
Their value is tied to the current market price of silver so it would be worth about $17 or $18 as of June 2008.
one dollar
It is worth what 1 oz of silver is worth which at the time of writing is $27.59 but silver changes in prices very frequently.
The coin is worth the 1 oz of silver, and nothing more
You need to state what the denomination is, I.E., 25 Cents. 50 Cents, 1 Dollar....FYI silver is worth about $30 per ounce.
A 1999 1oz silver dollar may be worth up to $50. The value is based on the value of silver at the time of sale. The price of silver changes nearly by the minute.
Probably around $22-25 USD.
$20-$60. Depending on what year it was made.
This is a bullion coin sold for its silver value, currently about $17/oz. The "$1" denomination is artificial.
As of 15 January 2014, it's worth $20.
whatever 1 oz. of silver is worth
The reverse side should state that it contains 1 oz of .999 fine silver. With the current price of silver around $14 per oz., that's its value.
Sorry, no 1956 silver dollars exist. Look at the coin again and post new question.