August 1866; its initial members were France, Belgium, Italy and Switzerland, and they agreed that their national currencies should be standardised and interchangeable. There was no shared, single legal tender, but the currencies of the member countries were pegged at a fixed rate with each other.
Two years later, the four founding nations were joined by Spain and Greece and in 1889 the union was further enlarged by admitting Romania, Bulgaria, Venezuela, Serbia and San Marino. Thus the enlarged Latin Monetary Union lasted until World War I, which abruptly brought to an end the global financial system based on the gold standard. The result was that the LMU effectively came to an end in 1914, although it lingered on as a legal entity until its formal dissolution in 1927.
http://www.bbc.com/news/magazine-1714037Interesting article on some LMU spec coins
http://www.coinweek.com/world-coins/wor ... ary-union/The US coins that met the standard were not an accident but a test as I understand it.