The gold standard was a commitment by countries to fix the prices of their domestic currencies in terms of a certain amount of gold. The gold standard converts the standard currency system into gold at a fixed price. The first time this was used was when England adopted a de facto gold standard in 1717 after master of the mint, Sir Isaac Newton, overvalued guinea in terms of silver. The gold standard was formally adopted by England in 1819. Before 1834 the United States used bimetallic currency system (silver and gold), they then switched to a gold de facto (gold standard) and was officially accepted in 1900. In 1834 the fixed price of gold was $20.67 per ounce, which lasted until 1933. The time period between 1880 to 1914 is known as the classical gold standard because that is when the majority of countries adhered to a gold de facto.