The United States dollar is the official currency of the United States and several other countries. The Coinage Act of 1792 introduced the U.S. dollar at par with the Spanish silver dollar, divided it into 100 cents, and authorized the minting of coins denominated in dollars and cents. U.S. banknotes are issued in the form of Federal Reserve Notes, popularly called greenbacks due to their predominantly green color.
Spanish silver eight-real or peso of 1768
Alexander Hamilton finalized the details of the 1792 Coinage Act and the establishment of the U.S. Mint.
Continental one third dollar bill (obverse)
Series of 1917 $1 United States Note
The dollar sign, also known as peso sign, is a currency symbol consisting of a capital ⟨S⟩ crossed with one or two vertical strokes, used to indicate the unit of various currencies around the world, including most currencies denominated "peso" and "dollar". The explicitly double-barred sign is called cifrão in the Portuguese language.
A piece of eight from the Potosí mint, showing the Pillars of Hercules with "S" ribbons, and two "PTSI" monograms at about 4 and 8 o'clock around the edge
Car for sale in Cape Verde, showing use of the cifrão as decimals separator
