A dollar traditionally has been a coin consisting of an ounce of silver. There have been many dollars issued, for example, by the governments or central banks of Australia, Belize, Canada, Hong Kong, New Zealand, Singapore, Taiwan, and the United States.
 Private dollars
In 2007, Angel Cruz of the United Cities Corporation created "United States Private Dollars." He was indicted for bank fraud and conspiracy to defraud, and is still a fugitive.
Circa 2009, a private group produced a Liberty Dollar whose $20 piece consisted of one ounce of .999 fine silver. This organization's leader, Bernard von NotHaus, was prosecuted and convicted by the U.S. government, the justification being that customers who received the coin in change were receiving "fake goods."
- Rothbard, Murray. "What Has Government Done to Our Money?". http://mises.org/money/2s5.asp. "The dollar began as the generally applied name of an ounce weight of silver coined by a Bohemian Count named Schlick, in the sixteenth century. The Count of Schlick lived in Joachim's Valley or Jaochimsthal. The Count's coins earned a great reputation for their uniformity and fineness, and they were widely called "Joachim's thalers," or, finally, "thaler." The name "dollar" eventually emerged from "thaler.""
- FBI (5 April 2011). "Private Tender". http://www.fbi.gov/news/stories/2011/april/dollar_040511.