|Currency Name:||United States dollar|
|Central Bank:||Federal Reserve|
|Number of Country & Territory Using United States Dollar:||17 Countries.|
|Country & Territory Officially Using United States Dollar:||American Samoa. Bonaire, Sint Eustatius and Saba. British Indian Ocean Territory. British Virgin Islands. East Timor (Timor Leste). Ecuador. El Salvador. Guam. Marshall Islands. Micronesia. Northern Mariana Islands. Palau. Puerto Rico. Turks and Caicos Islands. United States. United States Minor Outlying Islands. United States Virgin Islands.|
|Banknotes:||Banknotes: $1, $5, $10, $20, $50, $100, (rarely used: $2, Discontinued & still legal tender: $500, $1,000, $5,000, $10,000).|
Coins: 1¢, 5¢, 10¢, 25¢, (Rarely used: 50¢, $1, ½¢ 2¢, 3¢ (Nickel), 3¢ (Silver), 20¢, $2.50, $3, $20, $5, $10).
The United States dollar (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, is the official currency of the United States and its territories. 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 its historically predominantly green color. The monetary policy of the United States is conducted by the Federal Reserve System, which acts as the nation's central bank.
The U.S. dollar was originally defined under a bimetallic standard of 371.25 grains (24.057 g) fine silver or, from 1837, 23.22 grains (1.505 g) fine gold, or $20.67 per troy ounce. The Gold Standard Act of 1900 linked the dollar solely to gold. From 1934 its equivalence to gold was revised to $35 per troy ounce. Since 1971 all links to gold have been repealed.
The U.S. dollar became an important international reserve currency after the First World War, and displaced the pound sterling as the world's primary reserve currency by the Bretton Woods Agreement towards the end of the Second World War. The dollar is the most widely used currency in international transactions. It is also the official currency in several countries and the de facto currency in many others, with Federal Reserve Notes (and, in a few cases, U.S. coins) used in circulation.