In 1865, France, Belgium, Italy, and Switzerland formed the Latin Monetary Union, in which they agreed to value their national currencies to a standard of 4.5 grams of silver or 0.290322 grams of gold. Even after the monetary union faded away in the 1920s and officially ended in 1927, the Swiss franc remained on that standard until 1936, when it suffered its sole devaluation, on 27 September during the Great Depression. The currency was devalued by 30% following the devaluations of the British pound, U.S. dollar and French franc. In 1945, Switzerland joined the Bretton Woods system and pegged the franc to the US dollar at a rate of $1 = CHF 4.30521 (equivalent to CHF 1 = 0.206418 grams of gold). This was changed to $1 = CHF 4.375 (CHF 1 = 0.203125 grams of gold) in 1949.