USD (United States Dollar)

The currency abbreviation for the United States dollar (USD), the currency for the United States of America. The United States dollar, or U.S. dollar, is made up of 100 cents and is presented with the symbol $ or US$ to differentiate it from other dollar-based currencies. The U.S. dollar is considered a benchmark currency, and is the currency used the most in transactions across the world. The currency is actually used as an official currency in many countries outside of the U.S., while many others use it alongside their own as an unofficial currency.

The United States dollar was originally created through the Coinage Act of 1792, which specified that a dollar of currency would be equal to between 371 and 416 grains of silver, and an "eagle" (US$10) at between 247 and 270 grains of gold. Gold coins with equivalent weights were used, and based on this system, the value of the dollar (in purchasing power), would be equivalent to the purchasing power of the gold or silver on which it was based.

In 1933, gold coins were taken back, and the gold standard was changed, setting the price of a troy ounce to $35. This gold standard continued until 1968, when a series of pegs to gold were put in place until 1975. In January of 1975, the U.S. dollar was removed from the gold standard, and was allowed to float freely on the international currency markets.