The dollar is the unit of currency of the United States.  Taken over by the Congress of the Confederation of the United States on July 6, 1785, the U.S. dollar is the currency most used in international transactions. Several countries use the U.S. dollar as their official currency, and many others allow it to be used in a de facto capacity.

The United States dollar is unique in the way that there have been more than 10 types of banknotes, such as Federal Reserve Bank Note, gold certificate, and United States

Colonial Scrip · Compound Interest Treasury Note · Demand Note · Federal Reserve Bank Note · Gold Certificate · Interest Bearing Note · National Bank Note · National Gold Bank Note · Refunding Certificate · Silver Certificate · Treasury or 'Coin' Note · United States Note

The Federal Reserve Note is the only type that remains in circulation since the 1970s.

Currently printed denominations are $1, $2, $5, $10, $20, $50, and $100. Notes above the $100 denomination ceased being printed in 1946 and were officially withdrawn from circulation in 1969.Notes in denominations of $500, $1,000, $5,000, $10,000, and $100,000 were all produced at one time.