<P> Silver pennies based on the Roman denarius became the staple coin of Mercia in Great Britain around the time of King Offa, circa 757--796 CE . Similar coins, including Italian denari, French deniers, and Spanish dineros, circulated in Europe . Spanish explorers discovered silver deposits in Mexico in 1522 and at Potosí in Bolivia in 1545 . International trade came to depend on coins such as the Spanish dollar, the Maria Theresa thaler, and, later, the United States trade dollar . </P> <P> In modern times, the British West Indies was one of the first regions to adopt a gold specie standard . Following Queen Anne's proclamation of 1704, the British West Indies gold standard was a de facto gold standard based on the Spanish gold doubloon . In 1717, Sir Isaac Newton, the master of the Royal Mint, established a new mint ratio between silver and gold that had the effect of driving silver out of circulation and putting Britain on a gold standard . </P> <P> A formal gold specie standard was first established in 1821, when Britain adopted it following the introduction of the gold sovereign by the new Royal Mint at Tower Hill in 1816 . The United Province of Canada in 1853, Newfoundland in 1865, and the United States and Germany (de jure) in 1873 adopted gold . The United States used the eagle as its unit, Germany introduced the new gold mark, while Canada adopted a dual system based on both the American gold eagle and the British gold sovereign . </P> <P> Australia and New Zealand adopted the British gold standard, as did the British West Indies, while Newfoundland was the only British Empire territory to introduce its own gold coin . Royal Mint branches were established in Sydney, Melbourne, and Perth for the purpose of minting gold sovereigns from Australia's rich gold deposits . </P>

When did the united states go on the gold standard