The United States  dollar (sign: $; code: USD) is the unit of currency of the United States 
The U.S. dollar is the currency most used in international transactions. Several countries use it as their official currency, and in many others it is the de facto currency.
The first dollar coins issued by the United States Mint (founded 1792) were similar in size and composition to the Spanish dollar. The Spanish and U.S.  silver dollars circulated side by side in the United   States New York 

