when did the us dollar become reserve currency
Reserve currency After World War II, the international financial system was governed by a formal agreement, the Bretton Woods System. Under this system the United States dollar was placed deliberately as the anchor of the system, with the US government guaranteeing other central banks that they could sell their US dollar reserves at a fixed rate for gold.[8]
United States dollar The United States dollar (sign: $; code: USD; also abbreviated US$ and referred to as the dollar, U.S. dollar, or American dollar) is the official currency of the United States and its insular territories per the United States Constitution. For most practical purposes, it is divided into 100 smaller cent (¢) units, but officially it can be divided into 1000 mills (₥). The circulating paper money consists of Federal Reserve Notes that are denominated in United States dollars (12 U.S.C. § 418).