The official currency of the United States of America. It is managed by the Federal reserve and is tasked with stabilizing prices and maximizing employment (the dual mandate).
The USD currency was created in 1792 with the inception of "The United States of America" (The United States), a nation state located in the North American continent.
From 1792 to 2019 it was the world's most traded currency, accounting for 87% of trading volume.
The USD was exchangeable for gold until 1933 when the United States decided it wasn't. In 1971, The United States went even further and declared that the USD was no longer backed by gold. The currency from then on was referred to as a "fiat" currency (backed only by the government that issued it).
Since 1913, the supply of the USD has been managed by an independent organization known as the Federal Reserve (The Fed). The Fed was created by the United States Government (USG) to soften the effects of business cycles (recessions and expansions). Specifically it was tasked with stabilizing prices and maximizing employment (the dual mandate).